YouTube2Text

Non Random Sampling — Transcript

by MCO-3 [RM&SA] · 6,454 words · 1,133 segments · language en · Watch on YouTube

Full transcript

  1. 0:00[Music]
  2. 0:08[Music]
  3. 0:14hello learners
  4. 0:15i am dr sabot sharwani working with
  5. 0:17indar gandhi national open university
  6. 0:19the topic which i am going to talk today
  7. 0:20is method of sampling part two
  8. 0:22which revolves around non-random
  9. 0:24sampling i think in our preceding two
  10. 0:26sessions
  11. 0:27if you recalculate yourself or you know
  12. 0:29visit the
  13. 0:30facebook live link you will find out
  14. 0:33that we
  15. 0:33the first session was you know talking
  16. 0:35about the sampling and when we have
  17. 0:36talked about the sampling we talk about
  18. 0:38how the sampling is
  19. 0:39quite important when we talk about the
  20. 0:41research when we talk about you know
  21. 0:42collection of data or when we talk about
  22. 0:44you know interacting with the
  23. 0:45respondents because
  24. 0:47there are certain mythologies which are
  25. 0:48going to play a very important role and
  26. 0:50then afterwards we have we have talked
  27. 0:52about you know the methods of sampling
  28. 0:54and talk about you know the first part
  29. 0:56which talks about the random sampling or
  30. 0:58rather we can say the probability
  31. 0:59sampling
  32. 1:00so in this probability sampling we have
  33. 1:02we have covered you know the various
  34. 1:03aspects
  35. 1:04that how the probability sampling
  36. 1:05differs from non-probability sampling
  37. 1:07or you know the random sampling differs
  38. 1:09from the non-random sampling so today's
  39. 1:11session you know talks about the
  40. 1:12non-random sampling
  41. 1:13which is also one of the important
  42. 1:15ingredients as far as you know the
  43. 1:16collection of data is concerned as far
  44. 1:18as the sampling is concerned so
  45. 1:20anyway prior to going into the depth of
  46. 1:21this topic let's you know quickly
  47. 1:23recapitulate ourselves what we have done
  48. 1:25in our preceding session
  49. 1:27and what exactly you know the points
  50. 1:28which had been taken care so that
  51. 1:30you know the blocks can be built and
  52. 1:32gradually we can
  53. 1:33mug up you know the the concept related
  54. 1:36to research or the research methodology
  55. 1:37or the statistical analysis so
  56. 1:40the first the very first lecture was
  57. 1:42talking about you know the curtain laser
  58. 1:43to research
  59. 1:44which usually talks about what exactly
  60. 1:46the research is and how research
  61. 1:49is going to play a very important role
  62. 1:50as far as the academicians are concerned
  63. 1:52as far as the academia is concerned as
  64. 1:54far as
  65. 1:54the corporate world is concerned or you
  66. 1:56know the present trading commerce is
  67. 1:57concerned
  68. 1:58because everywhere research is coming up
  69. 2:00in a big way and we have observed that
  70. 2:03there was a time when research was
  71. 2:04confined to to the university systems or
  72. 2:07to the
  73. 2:08academic institutions or the research
  74. 2:09institution but now it had crosses the
  75. 2:11boundaries
  76. 2:11and everywhere you find out even the
  77. 2:14most omnipresent thing which
  78. 2:16which the corporates are doing right now
  79. 2:17it's doing the research of the consumers
  80. 2:19or knowing about the behavior about the
  81. 2:21consumers so
  82. 2:23we are not going more into the depth of
  83. 2:25it because already we have a very
  84. 2:26thought provoking sessions which can uh
  85. 2:29provide a link to the
  86. 2:31learners to go through into that so then
  87. 2:33we have talked about the research
  88. 2:34thought
  89. 2:34how research thoughts are coming and how
  90. 2:37on the basis of you know the research
  91. 2:38thought you can build your
  92. 2:40future plan of action of research then
  93. 2:42there are certain faqs which are going
  94. 2:44to play a very important role
  95. 2:45like the frequently asked questions at
  96. 2:48that when we are going to the research
  97. 2:49when we are going to choose the title
  98. 2:51or when we are going to formulate the
  99. 2:53objectives or what could be the modus
  100. 2:54operandi behind that so this whole
  101. 2:56research methods talks about that then
  102. 2:58we have research plan research problem
  103. 2:59because
  104. 3:00while starting your research you know
  105. 3:01the certain problems comes into picture
  106. 3:03and so the planning is going to play a
  107. 3:05very important role and if you have
  108. 3:06planned the things in a very systematic
  109. 3:08manner i think
  110. 3:09up to some extent you can resolve your
  111. 3:11way of doing the things so
  112. 3:12then we have formulation of objectives
  113. 3:15how the objectives you know
  114. 3:16can be framed then hypothesis was there
  115. 3:18because this hypothesis is quite
  116. 3:20important because when you're going to
  117. 3:21into the depth of the research i think
  118. 3:23the the first building block is is
  119. 3:25they're used to
  120. 3:26is to you know having a null hypothesis
  121. 3:28or then you can
  122. 3:29work on the basis of these hypotheses
  123. 3:31which can extract from the objectives
  124. 3:33which we used to do so
  125. 3:34research design is there then collection
  126. 3:36of data is there which usually talks
  127. 3:37about you know sample
  128. 3:39uh secondary data and primary data and
  129. 3:41then sampling is there so
  130. 3:42in our last to last session we have
  131. 3:44talked about the sampling
  132. 3:46and the the very last session was random
  133. 3:49sampling so
  134. 3:50probability sampling is there so now
  135. 3:53uh the very important thing is that why
  136. 3:55we go for uh sampling this we have
  137. 3:57already talked about this is a very
  138. 3:58important aspect because universal and
  139. 4:00population is a very gigantic shape
  140. 4:02and it's really cumbersome for the for
  141. 4:04the individual for the researchers to
  142. 4:06you know
  143. 4:06go into the depth of all the population
  144. 4:08or the universal and come to the
  145. 4:09conclusion so
  146. 4:10that is where you know the the concept
  147. 4:12of the sampling comes
  148. 4:14and the collection of sample comes into
  149. 4:15picture so from there you know the
  150. 4:17things had need to be come up
  151. 4:18and then there are certain methodologies
  152. 4:21which are
  153. 4:22very important and when you talk about
  154. 4:23the random sampling we have already
  155. 4:25talked about you know the random
  156. 4:26sampling
  157. 4:26and we have seen that how the
  158. 4:28bifurcation of random sampling is there
  159. 4:30because
  160. 4:31uh the very important thing is that the
  161. 4:34that random sampling talks about you
  162. 4:35know the sampling outlier
  163. 4:37outlier is is a very important
  164. 4:39ingredient because
  165. 4:40when we study the statistics when we go
  166. 4:43into the depth of measure of central
  167. 4:45tendency
  168. 4:46there you know we have a very stereotype
  169. 4:48methods that is uh
  170. 4:50mean median and mode and these mean
  171. 4:53median modes
  172. 4:54lacks you know when the outlier comes
  173. 4:56because when you go for the average
  174. 4:58average in general you know are in
  175. 5:00certain intervals or you know
  176. 5:02link to one another but sometimes what
  177. 5:04happens when you take average sometimes
  178. 5:06you know the figure comes like 5 10 15
  179. 5:08and sometimes comes at 90.
  180. 5:09if you take average of all three i think
  181. 5:12the averages could be somewhat
  182. 5:13differs whereas if you so that that 90
  183. 5:16is nothing but
  184. 5:17outlier because it is different from
  185. 5:19from the other other sample numbers
  186. 5:20which you have taken so
  187. 5:22then you have then you are going to
  188. 5:24apply the measure of central
  189. 5:26standard deviation or measure or
  190. 5:28dispersion or other way of doing things
  191. 5:29so
  192. 5:30that is the model which is there where
  193. 5:32when you are emphasizing more on the
  194. 5:33random sampling i think the random
  195. 5:35sampling always emphasize on
  196. 5:37sampling outliers which is somewhat
  197. 5:39lacking so that is the reason you know
  198. 5:40we have to come out from there
  199. 5:42and we have to apply this
  200. 5:44non-probability sampling so anyway
  201. 5:47we are just going to throw a light on
  202. 5:49what exactly the non-random sampling is
  203. 5:51because
  204. 5:52when you talk about the sampling i think
  205. 5:54is a study of research involves a large
  206. 5:55number of population we have already
  207. 5:56talked about
  208. 5:57and you see universe is at the at the
  209. 6:00top then you have sensor then your
  210. 6:01sample population then
  211. 6:02sample frame and then from here from
  212. 6:05here you are going to
  213. 6:07take the elements or collect the data so
  214. 6:10these are the points which we have
  215. 6:11already covered in our preceding
  216. 6:12sessions
  217. 6:13and what could be the sample is what are
  218. 6:16the essentials of good sample then
  219. 6:17random sampling methods
  220. 6:18and and today we are going just focus on
  221. 6:22non-probability
  222. 6:23methods so when you are going to talk
  223. 6:25about the
  224. 6:26probability methods i think we have
  225. 6:28already talked about it's a random
  226. 6:29sampling does not involve human judgment
  227. 6:32requires sampling frame and the
  228. 6:35the you know the methodologies are
  229. 6:37systematic stratified cluster
  230. 6:39or you know the simple random sampling
  231. 6:41whereas when you talk about the non
  232. 6:43probability methods it is you know the
  233. 6:45it involves human judgment
  234. 6:47and it has sampling frame required and
  235. 6:49it is you know called the quota sampling
  236. 6:51convenience sampling judgment sampling
  237. 6:53or you know this snowball
  238. 6:56sampling so uh so we are going to
  239. 6:59gradually talk about and distinguish how
  240. 7:00this
  241. 7:01probability sampling refer differs from
  242. 7:04non-probability sampling because
  243. 7:05when you are going to talk about the
  244. 7:06probability sampling i think if you see
  245. 7:08this particular image
  246. 7:09this this probability sampling is quite
  247. 7:12scattered in nature whereas
  248. 7:13non-probability sampling is quite
  249. 7:14purposive in nature
  250. 7:16and and it is in a in a very systematic
  251. 7:18manner you are going to take so somewhat
  252. 7:20you know the
  253. 7:20model is like that whereas when you are
  254. 7:22going to talk about the probability
  255. 7:23sampling you are not
  256. 7:25biased whereas when you are going to
  257. 7:26talk about the uh this non-probability
  258. 7:28sampling you are very much biased
  259. 7:30so this is a thing which is there and
  260. 7:33now
  261. 7:34we have got a very very important
  262. 7:35comparison which can distinguish
  263. 7:38that what is the difference between what
  264. 7:39is the actual difference between you
  265. 7:40know
  266. 7:41the probability sampling and
  267. 7:42non-probability sampling and that is
  268. 7:44quite important because once you are
  269. 7:45going to depth of
  270. 7:46non probability sampling there must be
  271. 7:48certain logic there must be certain
  272. 7:50justification
  273. 7:51if you are not going to provide the
  274. 7:53justification i think some way you are
  275. 7:55going to lack because
  276. 7:56because what happened when we when we
  277. 7:58are in the process of
  278. 7:59collection of of data or taking the
  279. 8:02sample or extracting the sample
  280. 8:03i think this this phenomena need to be
  281. 8:06understand in a very
  282. 8:08contemporary manner so if you see this
  283. 8:11probability sampling is a sampling
  284. 8:12technique in which the subjects of the
  285. 8:14population get an equal opportunity to
  286. 8:16be selected
  287. 8:17as a representative sample we have seen
  288. 8:18in the cluster sampling we have seen in
  289. 8:21the you know
  290. 8:21the stratified random sampling that we
  291. 8:24make certain strata we make certain
  292. 8:26group
  293. 8:26and from that group you know some of the
  294. 8:28representation need to be done
  295. 8:30so there must be a model where equal
  296. 8:32opportunities need to be given
  297. 8:34and there must be a representative from
  298. 8:36e sample so that is the beauty of
  299. 8:38probability sampling which we have
  300. 8:40studied elaborately in our preceding
  301. 8:41session
  302. 8:42and if you talk about non-probability
  303. 8:44sampling i think non-probability
  304. 8:45sampling is a method of sampling wherein
  305. 8:47it is known that which individuals from
  306. 8:50the population will be selected as
  307. 8:51sample because
  308. 8:52so that could be the reason you know if
  309. 8:54you talk about probability sampling it
  310. 8:55could be
  311. 8:56not biased whereas non-probability
  312. 8:58sampling is quite biased because you
  313. 8:59talk about you know the convenient
  314. 9:00convenience sampling
  315. 9:02or you know judgmental sampling or the
  316. 9:03quota sampling
  317. 9:05or even the snowball sampling or
  318. 9:06purposive sampling so everywhere you
  319. 9:08observe that you know you are quite
  320. 9:10familiar that you are going to collect
  321. 9:12the data from from this manner
  322. 9:13and and that from this particular class
  323. 9:15increase so you are quite biased in that
  324. 9:18and if you talk about the convenience
  325. 9:20sampling
  326. 9:21you are you know for your convenience
  327. 9:23like you know
  328. 9:24you are doing your research in in delhi
  329. 9:27or in
  330. 9:27particular state so you have gone for
  331. 9:29the convenience sampling because you are
  332. 9:31reciting to that particular state and it
  333. 9:32would be easier for you to collect the
  334. 9:34data
  335. 9:34or collect the sample so that could be
  336. 9:36the reason you are emphasizing more on
  337. 9:38convenience sampling so and and some
  338. 9:41certain times
  339. 9:42when we go more into the depth of the
  340. 9:43judgmental sampling or the snowball
  341. 9:45sampling
  342. 9:46which is quite talking about
  343. 9:49cross layer model where the reference is
  344. 9:52going to play a very important role so
  345. 9:54that is the thing which is there so
  346. 9:55alternatively known as random sampling
  347. 9:57this is known as non random sampling
  348. 9:59and basis of selection is randomly that
  349. 10:00is very true and
  350. 10:02randomly you are going to select the
  351. 10:04content or you know the sample from pro
  352. 10:07if you're talking about the probability
  353. 10:08sampling but if you are talking about
  354. 10:10non-random probability sampling or non
  355. 10:11random sampling you are arbitrarily
  356. 10:13taking the
  357. 10:14sample so opportunity of selection is
  358. 10:16fixed and known that is very true and
  359. 10:18not specified in unknown
  360. 10:20so research is conclusive it's very true
  361. 10:22and end of the result what you are going
  362. 10:23to get
  363. 10:24you are going to get a very conclusive
  364. 10:25result which is which is quite holistic
  365. 10:27in nature whereas
  366. 10:28whereas when you are talking about
  367. 10:30non-probability sampling it is quite
  368. 10:31exploratory
  369. 10:32we will see there are certain methods
  370. 10:34like snowball
  371. 10:35uh nonven sampling methods which
  372. 10:39which purely based on the reference like
  373. 10:41we will send
  374. 10:42the questionnaire to respondents and ask
  375. 10:45the respondents to
  376. 10:46provide a certain you know the lead and
  377. 10:48on the basis of that lead we can again
  378. 10:50you know
  379. 10:51hit that particular respondents and ask
  380. 10:53certain questions from them so this
  381. 10:55could be the modus operandi
  382. 10:56which talks about that how the
  383. 10:58exploratory studies there and these are
  384. 10:59quite consuming you know
  385. 11:01and it's quite holistic in nature and
  386. 11:03and takes into consideration you know
  387. 11:05the time factor and other things so
  388. 11:07results are unbiased
  389. 11:08and results are biased because you are
  390. 11:11quite
  391. 11:11the example which i have quoted about
  392. 11:13you know the convenience sampling that
  393. 11:14you are
  394. 11:15for your convenience you are going and
  395. 11:17and choosing the particular judicials
  396. 11:19and you know that if you go for other
  397. 11:21jurisdictions maybe some different
  398. 11:22results will come but
  399. 11:23it's really cumbersome for you to you
  400. 11:25know collect the data from different
  401. 11:26states so since you have
  402. 11:28confined yourself to the particular
  403. 11:31judicion i think you are quite biased in
  404. 11:33that manner so
  405. 11:34this is the model which is there and
  406. 11:37methods are objective
  407. 11:39that is very true you are quite object
  408. 11:41oriented whereas
  409. 11:42methods are subject-oriented and you
  410. 11:44could be quite subjective
  411. 11:46and as far as the inferential inferences
  412. 11:49is concerned as far as
  413. 11:50you know the thing is concerned this
  414. 11:53probability sampling talks about the
  415. 11:54statistical way of doing the things and
  416. 11:57non-probability sampling talks about the
  417. 11:59analytical way of doing that thing so
  418. 12:01here you know the hypothesis is need to
  419. 12:03be tested when you are going to talk
  420. 12:04about the probability sampling
  421. 12:05whereas here the hypothesis need to be
  422. 12:07generated so sometimes what happen
  423. 12:09uh when you are you know uh applying the
  424. 12:12non-probability sampling
  425. 12:13you get certain hypotheses which need to
  426. 12:15be generated or it could not be
  427. 12:18it could not be an alternative
  428. 12:19hypothesis but it can be a new kind of
  429. 12:21hypothesis which can again added in this
  430. 12:23list of hypotheses so
  431. 12:26the impact of these kind of
  432. 12:28non-probability sampling is that
  433. 12:30somewhere after certain time what you
  434. 12:32observe that that
  435. 12:34that your research could be lingered
  436. 12:36down some in some of the cases so anyway
  437. 12:38we have very very elaborately compared
  438. 12:41the term called
  439. 12:42this particular thing so non-probability
  440. 12:44or non-random sampling is a process of
  441. 12:46selecting sampling from a population
  442. 12:48without using statistical probability
  443. 12:50theory and
  444. 12:52if you talk about you know the
  445. 12:53non-probability sampling theory each
  446. 12:55element of member of the population does
  447. 12:56not have an equal chance
  448. 12:58of being included in the sample and the
  449. 12:59researchers cannot estimate the error
  450. 13:01cost by not collecting data
  451. 13:03from all elements member of the
  452. 13:05population so that is where which is
  453. 13:06which is there and if you go more into
  454. 13:08the depth of this non-probability
  455. 13:10sampling i think
  456. 13:10it's quite purposive in nature and that
  457. 13:12has to do with sampling
  458. 13:14addressing the question for research and
  459. 13:16the research sample is qualitative type
  460. 13:18and the probability sampling focus on
  461. 13:21external value for transferring of
  462. 13:22issues
  463. 13:23and the very important thing is that the
  464. 13:26series and control of sample is
  465. 13:27non-probability random sampling
  466. 13:28typically
  467. 13:29smaller than 30 cases again so in every
  468. 13:32junction you will observe that you are
  469. 13:33quite biased and
  470. 13:34you are quite you know making the things
  471. 13:36as per your convenience as per your need
  472. 13:38so that that could be the reason you
  473. 13:40know the result which used to come
  474. 13:43it have a very short-sighted approach
  475. 13:45and not
  476. 13:46giving the very holistic view or the or
  477. 13:48the robust report so
  478. 13:49non probability sampling have numerous
  479. 13:51sample of size which is determined by
  480. 13:53the purpose of particular x
  481. 13:55component and and this is you know
  482. 13:59using more rigid side estimation
  483. 14:00procedures so when we are going to talk
  484. 14:02about you know the certain types of
  485. 14:04these judgmental convenience purposes or
  486. 14:06snowball
  487. 14:07or you know the quota sampling we will
  488. 14:09see that how this non-random sampling
  489. 14:12differs from from the random sampling
  490. 14:15and what are the usp behind that so the
  491. 14:17methods are non-probability random
  492. 14:18sampling use
  493. 14:19wide range of sampling techniques so the
  494. 14:21reason behind is quite clear that
  495. 14:24sometimes what happen we are not in a
  496. 14:25position to collect the data
  497. 14:27or not you know getting an opportunity
  498. 14:30that respondents are
  499. 14:31reciprocating to us in that manner so
  500. 14:34what exactly we are going to do
  501. 14:35we are applying the certain methods
  502. 14:38which are quite important so
  503. 14:39in general we have four important
  504. 14:42ingredients which are
  505. 14:43part of non-probability sampling that is
  506. 14:45convenient sampling judgmental sampling
  507. 14:47quota sampling and snowball sampling so
  508. 14:51ah if we if we start with you know the
  509. 14:53non-probability sampling
  510. 14:55i think that this convenience sampling
  511. 14:58is talks about in the members of
  512. 14:59populations which are selected that are
  513. 15:00easily available for study
  514. 15:02and if you talk about the quota sampling
  515. 15:03sample generated by dividing the
  516. 15:05population to separate groups
  517. 15:06and selective members from each group
  518. 15:08that is non-representative quota
  519. 15:10and like you know we have taken we are
  520. 15:12going to take a data off
  521. 15:13of the mail which is of 50 years or you
  522. 15:16know taking the
  523. 15:17data of females of of of between you
  524. 15:20know 24 to 30 years so
  525. 15:22we have restrict ourselves so that could
  526. 15:23be the model by which you know the quota
  527. 15:25sample used to work
  528. 15:26and when you are going to talk about the
  529. 15:27snowball sample this sample in which
  530. 15:29members of the sample select further
  531. 15:31members for inclusion in the sample so
  532. 15:32here what happened we first float the
  533. 15:34information
  534. 15:35float the questionnaire to respondents
  535. 15:38and then ask the respondents to give us
  536. 15:39certain
  537. 15:40references so this is this works with
  538. 15:43the
  539. 15:44in a model called multi-level marketing
  540. 15:46or network marketing or
  541. 15:47or you know the reference uh procedures
  542. 15:50where
  543. 15:51the if we interact with one person the
  544. 15:52other person can give the reference of
  545. 15:54three
  546. 15:54and this could be the model so while you
  547. 15:56know elaborately talking about this
  548. 15:57snowball sample we will
  549. 15:59very easily view that how the things are
  550. 16:01going to be changing self-selecting
  551. 16:02purposive sample is there which in which
  552. 16:04member of population
  553. 16:06select themselves for inclusion in the
  554. 16:07sample so anyway i think
  555. 16:10this is another difference which talks
  556. 16:12about
  557. 16:13that how the things are going to be
  558. 16:14changed and there are certain advantages
  559. 16:16there are certain
  560. 16:18cost and degree and there are certain
  561. 16:19disadvantages also so if you talk about
  562. 16:22convenience is very low cost
  563. 16:24extensively used if you talk about
  564. 16:26judgment
  565. 16:27it's moderate cost average use and if
  566. 16:29you talk about quota moderate
  567. 16:30cost very extra extensively use and low
  568. 16:33cost use in special situation that for
  569. 16:35the snowball
  570. 16:36model is concerned so we start with the
  571. 16:38purpose of sampling
  572. 16:39and we will cover you know all the five
  573. 16:41heads which comes under the ambit of
  574. 16:44methods of sampling as far as the non
  575. 16:45random sampling is concerned we see that
  576. 16:47this purpose is sampling is quite biased
  577. 16:49in nature and
  578. 16:51from the very beginning you know you
  579. 16:52observe that that deliberately
  580. 16:54the person which had been taken
  581. 16:56extracted or you know the sample which
  582. 16:58need to be taken is quite biased so
  583. 17:00this is called purposive sampling we
  584. 17:01have we have populations and purposes of
  585. 17:03sampling is
  586. 17:04that we are biased that we are going to
  587. 17:06take only you know the black color
  588. 17:08uh person as a sample so we have taken
  589. 17:10only that only so this is the model
  590. 17:12which is there if you talk about
  591. 17:13snowball sampling this is a chain
  592. 17:15referral sampling and
  593. 17:16if you see this chain reference sampling
  594. 17:18this this chain referrals
  595. 17:20works in the manner which i am talking
  596. 17:22about that the multi-level marketing or
  597. 17:23the
  598. 17:23network marketing where the chain is
  599. 17:25there so while you know
  600. 17:27floating the sample to one person now we
  601. 17:30have taken a reference of
  602. 17:32two person from this person and these
  603. 17:34two person had given a difference of
  604. 17:36three more so one person had given a
  605. 17:37reference of three other had given a
  606. 17:39reference of three
  607. 17:40now from that three we have got you know
  608. 17:42the huge number of samples
  609. 17:44so these are considered to be a mouth
  610. 17:46marketing model or you know the way
  611. 17:48where we have we have seen and how the
  612. 17:50things are going to be
  613. 17:51moved and snowball sampling or chain
  614. 17:54reference sampling is defined as a non
  615. 17:55probability sampling techniques
  616. 17:57and which have crates that are rare to
  617. 17:59find and
  618. 18:00the this sample technique in which
  619. 18:02existing subjects provide refers to
  620. 18:04recruit samples
  621. 18:05so and this is sometimes you know quite
  622. 18:08important and this sampling method
  623. 18:09involves a primary data source
  624. 18:11nominating other potential data source
  625. 18:13so what exactly we are doing that when
  626. 18:15we formulate objectives when we
  627. 18:16on the basis objective we frame the
  628. 18:18hypothesis and on the basis of
  629. 18:20you know this hypothesis we
  630. 18:24frame the questionnaires and then these
  631. 18:26questionnaires are sent to the
  632. 18:27respondents
  633. 18:28and once the respondents reciprocates
  634. 18:31then what
  635. 18:32exactly we are going to do we can
  636. 18:35know we can very easily know that that
  637. 18:37you know the
  638. 18:38reciprocation is very less the
  639. 18:40respondents are not reciprocating
  640. 18:42the manner they're supposed to do so
  641. 18:44what exactly we are
  642. 18:46going to do in that case we take a
  643. 18:47reference from from these
  644. 18:49you know the the respondents that why
  645. 18:51not you can give us some more reference
  646. 18:53so
  647. 18:53and this nominating other potential data
  648. 18:55source is there and
  649. 18:56and this snowball sampling method is
  650. 18:58purely based on reference
  651. 19:00that is very true and uh it either it
  652. 19:02could be and these referrals are are you
  653. 19:04know
  654. 19:05uh are coming in due course of you know
  655. 19:07the collection of primary data it's not
  656. 19:08like that
  657. 19:09that you're going to collect the data so
  658. 19:11the the respondents the the bona fide
  659. 19:13respondents to whom you have floated the
  660. 19:15questionnaires
  661. 19:16they can give the the the references
  662. 19:19or they can give the referrals so these
  663. 19:20referrals are are you know
  664. 19:22and when the when you are making a
  665. 19:24question here you should you know design
  666. 19:25a question in such a manner
  667. 19:27that in this this particular question
  668. 19:28here you are going to ask
  669. 19:30you know the referrals so this snowball
  670. 19:33sampling is a popular business study
  671. 19:34method
  672. 19:35and which is which is going on the way
  673. 19:37things are going to be done because
  674. 19:38the way e-commerce companies are going
  675. 19:40to do the research or
  676. 19:42you know the the other
  677. 19:45way of research is coming out we have
  678. 19:48observed that this snowball sampling
  679. 19:49method extensively used where population
  680. 19:51is unknown and rare and it is tough to
  681. 19:53choose subject to assemble them as a
  682. 19:54sample for research so
  683. 19:56then we have observed that this
  684. 19:57convenience sampling is
  685. 19:59is is a very is a different method which
  686. 20:01talks about collection
  687. 20:02collecting data quickly and fewer rules
  688. 20:06to follow
  689. 20:07and this is again you know inexpensive
  690. 20:09methodology
  691. 20:10and easy to do research and this if you
  692. 20:13talk about the strength and weakness
  693. 20:15because when we are going to do the
  694. 20:16sampling
  695. 20:17we always do the swot analysis that that
  696. 20:18is strength weakness opportunity and
  697. 20:20threat
  698. 20:21and when we check these two parameters i
  699. 20:23think strength
  700. 20:24this is low cost time and administration
  701. 20:26high participation and generalization
  702. 20:27because
  703. 20:28uh because you know as far as the
  704. 20:30convenience sampling is concerned it's
  705. 20:31quite convenient you
  706. 20:32you can define the jourdains you can
  707. 20:34define your population and sometimes you
  708. 20:36can define your sample also
  709. 20:38so what exactly we um what what exactly
  710. 20:40we mean to say
  711. 20:41if you talk about the weakness it's
  712. 20:43generalizing subjects id population
  713. 20:45results depend on the characteristics of
  714. 20:47sample so
  715. 20:49this convenience sampling is defined as
  716. 20:50a method adopted by researchers
  717. 20:52where they collect market research data
  718. 20:54from a conveniently available pool of
  719. 20:56respondents so
  720. 20:57you have got a pool of respondents and
  721. 20:59you can very easily you know
  722. 21:01as per your convenience as per your you
  723. 21:02know pace you can collect the data
  724. 21:04so it is most common use sampling
  725. 21:06techniques as it is incredible prompt
  726. 21:08uncomplicated and economical so
  727. 21:10researchers use convenience sampling in
  728. 21:12situations where additional inputs are
  729. 21:13not necessary for the principal research
  730. 21:15and the components of the population are
  731. 21:17eligible and dependent on the
  732. 21:18researchers proximity to get involved in
  733. 21:20the sample so we have seen that
  734. 21:22that as far as the convenience sampling
  735. 21:24is concerned we have seen that how the
  736. 21:25researcher had
  737. 21:26had taken no purple figures in the
  738. 21:29sample so he had just taken you know
  739. 21:31only the sample
  740. 21:32which is which is away from the purple
  741. 21:34colors
  742. 21:35so this is a convenient sampling so
  743. 21:36again what i mean to say when you are
  744. 21:38going to talk about the non-random
  745. 21:39sampling it is quite biased in nature
  746. 21:41because this is you know somewhat
  747. 21:44talking about
  748. 21:44the convenience so select any member of
  749. 21:46the population work conveniently and
  750. 21:48readily available
  751. 21:49and then there are certain applications
  752. 21:51of convenience sampling so convenience
  753. 21:52sampling is applied
  754. 21:53by brands and organization to measure
  755. 21:55their perception of the image in the
  756. 21:57market
  757. 21:58that is very true because they can they
  758. 22:00can know about you know the brand
  759. 22:01loyalty they can know about the usage or
  760. 22:03the behavior of the consumers
  761. 22:05vis-a-vis to particular product so data
  762. 22:07is collected from potential customers to
  763. 22:08understand
  764. 22:09specific issues so there is always a
  765. 22:12chance that randomly selected population
  766. 22:14may not accurately represent the
  767. 22:15population of interest
  768. 22:17thus increasing the chance of bias so so
  769. 22:19anyway i think
  770. 22:21if you talk about you know the
  771. 22:22judgmental sampling which is again you
  772. 22:24know the
  773. 22:25the fourth ingredient of of this
  774. 22:26particular methods of sampling
  775. 22:29which we usually call non-random
  776. 22:31sampling i think this consumes minimum
  777. 22:33time for execution
  778. 22:35and directly approachable to respondents
  779. 22:37because
  780. 22:38and almost real time results are coming
  781. 22:40up so
  782. 22:41that is the reason you know you observe
  783. 22:42that when any e-commerce company sold
  784. 22:44the product
  785. 22:45they just put the budge on there on
  786. 22:47their portal and the
  787. 22:49the moment this consumers log in the
  788. 22:52particular portal
  789. 22:54or do the e-commerce the it asks for you
  790. 22:56know what your experience related to the
  791. 22:57particular
  792. 22:58product which you have ordered you know
  793. 23:00or two days back so
  794. 23:02in that case what we observe that this
  795. 23:03is considered to be a
  796. 23:05going to give the real time results and
  797. 23:07easy to conduct it quite easy to conduct
  798. 23:09because
  799. 23:10uh because the moment consumer login i
  800. 23:12think the first
  801. 23:13you know the budge or the question comes
  802. 23:15uh from the e-commerce portal to the
  803. 23:17consumers that
  804. 23:18that how you are going to how what do
  805. 23:19you think about the product and
  806. 23:21how we can you know enhance our services
  807. 23:24or other models so
  808. 23:25this is the thing which is there's
  809. 23:26another form of convenience sampling
  810. 23:27where participants are handpicked
  811. 23:29from the accessible population
  812. 23:31researchers select participants that are
  813. 23:33representative of the entire population
  814. 23:35and very subjective sample method can be
  815. 23:37biased so judgmental sampling is a form
  816. 23:39of convenience sampling or we can say in
  817. 23:40which the population elements are
  818. 23:42selected
  819. 23:42and based on the judgment of the
  820. 23:44researchers so sometimes again you know
  821. 23:47this is quite biased and when you are
  822. 23:49going to compare with the random
  823. 23:50sampling because
  824. 23:51the in this case also they as far as the
  825. 23:54final
  826. 23:54opinion is going to be considered the
  827. 23:56researcher role is very important and he
  828. 23:58is going to
  829. 23:58do the sampling as per the up its
  830. 24:01convenience and as per his judgment
  831. 24:03so test markets purchase engineers
  832. 24:04selected industrial market research
  833. 24:06expert witness used in court so these
  834. 24:09are considered to be the judgmental
  835. 24:10sampling and then you have
  836. 24:12got a quota sampling so if you talk
  837. 24:13about you know the quota sampling
  838. 24:15this it had also certain strength and
  839. 24:18weakness
  840. 24:18and its low cost time and administration
  841. 24:22is involved high participation in
  842. 24:24generalization that is very true
  843. 24:25and more representative of individual
  844. 24:27population the example which i have
  845. 24:28quoted about
  846. 24:29you know choosing you know the teenagers
  847. 24:32who are who are you know between in the
  848. 24:34bracket of
  849. 24:3515 to 18 years or if you talk about
  850. 24:38weakness generalizing subjects id
  851. 24:40population results depend on
  852. 24:41characteristic
  853. 24:42sample more time consuming so one one
  854. 24:45type of this is
  855. 24:46another type of non-probability sampling
  856. 24:47and must begin with the matrix of target
  857. 24:49population characteristic that is
  858. 24:51percentage males percentage females uh
  859. 24:54ses etc
  860. 24:55the set quota percentage of each
  861. 24:57character is fulfilled in the
  862. 24:58sample so there are certain advantages
  863. 25:01again because quota sampling means to
  864. 25:02take a very tailored sample
  865. 25:04and easy to administer fast to create
  866. 25:07and complete
  867. 25:08inexpensive and takes into account
  868. 25:10population proportions if desired
  869. 25:12and can be used if probability sampling
  870. 25:14techniques are not possible
  871. 25:16so what we observe that sometimes what
  872. 25:18happens there are certain probability
  873. 25:19sampling
  874. 25:20which which is not you know applicable
  875. 25:22so in that case you know the quota
  876. 25:23sampling is going to be done
  877. 25:25so this quota sampling is
  878. 25:28taken massively by by the by the
  879. 25:30governments and selection is not random
  880. 25:32selection
  881. 25:33bias poses a problem for example you
  882. 25:34might avoid choosing people
  883. 25:36who live farther away or people in rough
  884. 25:37neighborhoods this may take the results
  885. 25:39unrepresentative of the
  886. 25:41population so this is a this is a model
  887. 25:43of quota sampling where you have seen
  888. 25:44that
  889. 25:45from this particular group from this
  890. 25:46particular uh thing
  891. 25:48you know the the male population had
  892. 25:51been
  893. 25:52taken and who are in the bracket of 50
  894. 25:55years so
  895. 25:56anyway i think i have talked a lot about
  896. 25:59this random sampling i have talked a lot
  897. 26:02about
  898. 26:03this non-random sampling and this and
  899. 26:06i have very you know very ah
  900. 26:09meticulously
  901. 26:11explained in the very beginning that
  902. 26:12sampling is a technique you know
  903. 26:14and it's not like that you can you can
  904. 26:16just you know uh
  905. 26:18consider the population or you know
  906. 26:20earmark the population or universal then
  907. 26:23just extract the data from that
  908. 26:24particular population there must be
  909. 26:26certain modus operandi
  910. 26:27there must be certain procedures there
  911. 26:29must be certain methods
  912. 26:30and when you are going to talk about the
  913. 26:32methods i think you have to
  914. 26:34first see what exactly the sampling is
  915. 26:36and how you're going to collect the
  916. 26:37sample and what could be the modus
  917. 26:39operandi you are going to do
  918. 26:40and what are the ways you are going to
  919. 26:41apply like you know the non-random
  920. 26:43sampling you are going to applying or
  921. 26:45you are going to apply the
  922. 26:47the probability sampling but you have to
  923. 26:50see you know what exactly the demand
  924. 26:52comes from as far as the researcher is
  925. 26:54concerned
  926. 26:55so the certain time you know what we
  927. 26:57observe that when we are doing our
  928. 26:59research i think
  929. 26:59and we have taken a population or the
  930. 27:02universal or we have earmarked the
  931. 27:04population we just to narrow down the
  932. 27:07research just to
  933. 27:08you know cut short the research or try
  934. 27:11to
  935. 27:11condense the research in a in a shorter
  936. 27:14span
  937. 27:15we try to follow a fast track mode or
  938. 27:17you know the shortcut methods
  939. 27:19which is which is no way permissible as
  940. 27:22far as the research is concerned so
  941. 27:23being a researcher
  942. 27:24you have to be quite elaborative you
  943. 27:26have to have a patience and you have to
  944. 27:28see that how you're going to do the
  945. 27:29sampling
  946. 27:30because the whole genesis behind the
  947. 27:32good research is the sample because
  948. 27:34the population is something which you
  949. 27:35have earmarked or the universal which
  950. 27:37you have
  951. 27:38explored this is something which can
  952. 27:40give you the boundary
  953. 27:41but when you are when you are going to
  954. 27:43play in that in that ground or in the
  955. 27:45boundary i think
  956. 27:46there you have to see because when you
  957. 27:49enter into the
  958. 27:50into the playground you have to very
  959. 27:52easily make up your mind that you're
  960. 27:53going to play cricket today you're going
  961. 27:55to play football or you're going to play
  962. 27:56other games
  963. 27:58if you know the intention is not clear
  964. 28:01in your mind that what exactly you're
  965. 28:02going to
  966. 28:03play i think somewhere you are confused
  967. 28:05so and uh
  968. 28:06it's and that that confusion is going to
  969. 28:09eradicate once you
  970. 28:10once you know about you know the basic
  971. 28:12phenomena of
  972. 28:13of the sampling or you know the methods
  973. 28:16of sampling
  974. 28:17these sampling techniques are are you
  975. 28:20know quite vibrant in nature and
  976. 28:21it is not like that that one sample you
  977. 28:24have used and you are rigid to that
  978. 28:26so sometimes what happens we start with
  979. 28:27the random sampling
  980. 28:29that is stratified sampling simple uh
  981. 28:31random sampling or you know
  982. 28:33the systematic sampling or you know the
  983. 28:35other way of doing the things
  984. 28:37but after certain time we realize that
  985. 28:39that
  986. 28:40that the data is not coming in the
  987. 28:41manner we have we have presumers
  988. 28:44are supposed to be do so in that case
  989. 28:46what exactly you have to do you have to
  990. 28:48work as a juggler which i have told in
  991. 28:49the in my preceding session also that
  992. 28:52you have to do the thing in such a
  993. 28:54manner that you can jump to the other
  994. 28:56modes of doing the things so if you have
  995. 29:00started the journey with
  996. 29:01with convenience sampling or the cluster
  997. 29:03sampling or the stratified sampling
  998. 29:04so because these these are the way by
  999. 29:07which you can
  1000. 29:08able to interpret the particular
  1001. 29:10clusters or if you talk about
  1002. 29:12the stratifieds random sampling you can
  1003. 29:14make certain groups and do the things
  1004. 29:15but
  1005. 29:16when you move from this convenience
  1006. 29:17sampling to judgmental sampling some way
  1007. 29:19it also helps
  1008. 29:20because it can give you an uh different
  1009. 29:22way of doing the things
  1010. 29:23and on the other hand what we observe
  1011. 29:25that you have started with the random
  1012. 29:27sampling then you have
  1013. 29:28moved to the non random sampling and
  1014. 29:30apply the snowball sampling now the
  1015. 29:32snowball sampling
  1016. 29:33is purely working on the on the
  1017. 29:34references or to the chain model
  1018. 29:36so if you if you interact with few
  1019. 29:39respondents and you ask these
  1020. 29:41respondents to give
  1021. 29:42the you know the details about the other
  1022. 29:45respondents where you can float your
  1023. 29:46questionnaire i think
  1024. 29:47this is one of the way by which you know
  1025. 29:49you can you can get your access more and
  1026. 29:51and these these respondents considered
  1027. 29:53to be the potential respondents
  1028. 29:55it's not like that you can you can
  1029. 30:00just moving isolately or or
  1030. 30:04exploding the things in a in a dark room
  1031. 30:06you are
  1032. 30:07quite knowing that that you are going to
  1033. 30:08do the things or you are just you know
  1034. 30:11going to the right researchers or right
  1035. 30:12respondents so i think
  1036. 30:14this is the beauty of the sampling and
  1037. 30:17and we
  1038. 30:17we know that when we when we start the
  1039. 30:19sampling when we do the sampling when we
  1040. 30:21apply certain techniques or methodology
  1041. 30:23certain errors comes in between and
  1042. 30:25these errors work as a alarm
  1043. 30:27alarm bell and once you get the data and
  1044. 30:31so the motors are printed like that once
  1045. 30:33you have reciprocates once once you have
  1046. 30:35started you know collecting the
  1047. 30:37uh the data from the respondents in the
  1048. 30:39primary mode
  1049. 30:40you try to evaluate those data after
  1050. 30:43it's not like that
  1051. 30:44that you have you have a sample size of
  1052. 30:47of 400 or 500 and 100 people have
  1053. 30:49reciprocate then you wait for another
  1054. 30:51400 and then come to the conclusion
  1055. 30:53it's not like that you the the movement
  1056. 30:55you know 100 people have reciprocates
  1057. 30:57you make a small you know competitive
  1058. 30:59view or
  1059. 31:00of the of the respondents reports and
  1060. 31:03try to find out
  1061. 31:04that what exactly uh you know
  1062. 31:07the things are coming out if you know
  1063. 31:09the results considered to be
  1064. 31:11appreciable or you know the considered
  1065. 31:14results considered to be
  1066. 31:17satisfactory then you can carry on with
  1067. 31:19that otherwise in
  1068. 31:20in between you have to apply certain
  1069. 31:22other methodologies which can give you a
  1070. 31:24model which can give you a platform
  1071. 31:26that that you reach to a a conclusion so
  1072. 31:30i think this could be the way and we
  1073. 31:32have to be quite
  1074. 31:33quite serious when we are doing
  1075. 31:37when we are in the process of collecting
  1076. 31:38a sample because the if you have
  1077. 31:39collected the sample of 100 respondents
  1078. 31:42and
  1079. 31:42and if you have made the competitive
  1080. 31:43view i think the interpretation could be
  1081. 31:46quite clear that whether you are moving
  1082. 31:47a right direction
  1083. 31:48or you know some some other points need
  1084. 31:51to be added in questionnaire which can
  1085. 31:52give you a more
  1086. 31:53more elaborative result so that is where
  1087. 31:55you know you have to stop yourself
  1088. 31:57or you have to revamp your questionnaire
  1089. 31:59and then you have to start your journey
  1090. 32:01so
  1091. 32:01so i think this this research when we
  1092. 32:04talk about the research when you talk
  1093. 32:05about the research plan
  1094. 32:06when we talk about the research design
  1095. 32:08it's not like that you have make the
  1096. 32:10research plan or design the very
  1097. 32:11beginning
  1098. 32:11you have to be quite you know agile or
  1099. 32:14or you know
  1100. 32:16be active as far as the research process
  1101. 32:18is going on so
  1102. 32:19every juncture you have to recapitulate
  1103. 32:21yourself you have to
  1104. 32:22see whether you are moving in a right
  1105. 32:24manner or or you know
  1106. 32:26what certain things would need to be
  1107. 32:27added or deleted or
  1108. 32:29you know subtracted so that you can
  1109. 32:31after certain time you read you need
  1110. 32:34lead to a final conclusion so anyway i
  1111. 32:36think we are going to
  1112. 32:38wind up this particular session which is
  1113. 32:39quite thought provoking and very
  1114. 32:41important as far as the
  1115. 32:42as far as the researcher is concerned
  1116. 32:44because sampling is is very important
  1117. 32:46ingredient
  1118. 32:46you know and in the next session we are
  1119. 32:49going to talk about the errors they are
  1120. 32:50margin of errors there are
  1121. 32:51statistical errors or sampling errors
  1122. 32:54and how these sampling errors are
  1123. 32:56are working as a alarm bell and how
  1124. 32:59you're going to come out because if you
  1125. 33:00are familiar with
  1126. 33:01with the with the pros and cons i think
  1127. 33:04the the result which you are used to get
  1128. 33:05it's quite foolproof in nature
  1129. 33:07so thank you learners we will have
  1130. 33:09another sessions in coming days thank
  1131. 33:11[Music]
  1132. 33:22you
  1133. 33:27you

About this transcript

This page contains the full transcript of Non Random Sampling by MCO-3 [RM&SA], generated from the public captions YouTube serves with the video. The transcript has 6,454 words across 1,133 segments, with the original timestamps preserved so you can click any line to jump to that moment in the embedded player.

What you can do with it

Use the transcript to take notes, quote the speaker, build a study guide, generate a summary with ChatGPT or Claude via the YouTube Summary tool, or export it as a timed subtitle file with YouTube to SRT. You can also re-open it in the transcriber to translate the transcript into 100+ languages.

Free YouTube transcript tool

YouTube2Text is a free YouTube transcript generator — no signup, no daily limit. Paste any YouTube link and get the full transcript instantly, with timestamps, click-to-jump, translation to 100+ languages, AI prompts for ChatGPT, Claude, and Gemini, and exports to TXT, SRT, VTT, or Markdown.