Flashcards
3] pop and sample & sampling techniques + implications
Flashcards do conjunto (19)
- 1populationgroup of people who are the focus of the researcher's interest , from which a smaller sample is drawn
- 2samplegroup of people who take part in a research investigation (sample is drawn from a target pop and is presumed to be representative of that population)
- 3sampling techniquesmethods used to select people from the population
- 4biaswhen certain groups are over or under represented within sample selected (eg too many younger people or too many with one ethnic origin in the sample)
LIMITS EXTENT TO WHICH GENERALISATIONS CAN BE MADE TO THE TARGET POPULATION - 5GENERALISATIONfindings and conclussions from aparticular investigation can be broadly applied to the population
(possible if sample of paryicipants is representative of the target population) - 6researcher's aimto generalise their findings from the sample to the target population
(assume that the results from the sample will apply to the rest of the target population - not always appropriate to do this for 2 reasons) - 7why is it not appropriate to assume that results from sample will apply to the rest of the target popSAMPLE SIZE - (If a researcher only uses a small number of partcipants then they unlikely have a sample that represents all the different types of people in the target pop- difficult to generalise results of the study back to them)
SAMPLING METHOD - (some sampling methods aim to select a range of different participants so the characteristics of the whole target pop are reflected in the characteristics of the sample - many sampling methods do not so it may not be appropriate to generalise the findings from this type of sample to the target population) - 8types of ways of selecting sample from the target population (SAMPING TECHNIQUES)- RANDOM
- OPPORTUNITY
- STRATIFIED
- SYSTEMATIC
- vOLUNTEER - 9OPPORTUNITY samplingsample taken using any convenient members of the target population who are willing and available to take part in study
ADV - not time consuming 9uses convenient and accessible memebrs of the target pop - unlikely to be time consuming - saves the reseracher's time and money)
DIS - Researcher BIAS (researcher selects participants for the sample- can influence who takes part- may select those most likely to produce results that will support their hypothesis) - decreases internal val
2. SAMPLE MAY NOT BE REPRESENTATIVE OF ALL TARGET POP/ biased- researcher selects sample themselves - may accidentally choose participants that are not representative of all diff people in target population - decreases the external pop validity of the study - not possible to generalise results to the target pop - 10VOLUNTEER SAPMLINGRESEARCHER USES MEMEBERS OF TARGET POP WHO HAVE PUT THEMSELVES FOWARD TO TAKE PART IN STUDY
ADV: researcher is simply required to write an advert - quick and easy to gather the sample (unless no one volunteers) - save time and money
DIS- SAMPLE MAY NOT BE REPRESENTATIVE OF ALL PEOPLE - sample made out of volunteer participants (may be similar to one another and may not be representative of all different people in target population) - decreases external pop validity of the study - not possible to generalise results to the target pop - 11RANDOM saplingevery member of target pop has an EQUAL chance of getting selected for the sample
- 12the researcher obtains names from everyone in the target pop and then uses one of the following techniquesMANUAL SELCTEION - puts names of every meber of target pop on separate slip of paper and place all in container. Researcher draws out names to be used in sample)
container should - be shaken between each draw , same size, foldede the same way , researcher should draw blind - can't see actual slips of paper)
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COMPUTER SELECTION - researcher assigns every member of target pop a number. Random generator programme is sued to produce a string of numbers which have no relationship to one another. First numbers generated are used to identify the participants that will be used in the sample - 13adv and Dis of random samplingNO RESEACHER BIAS - (all members have an = chance of being selected, researcher can't influence who takes part, can't select who are likely to produce results that the researcher wants) - increases internal Val
SAMPLE UNLIEKLY TO BE REPRESNTATIVE OF THE TARGET POP - all members of the t pop have an = change of being selected - quite likely all the different types of people that make up the target pop will be represented in the sample (especially is sample is big) - increases internal pop val - possible to generalise results to target pop - NOT GURANTEED A SAMPLE THAT IS REPRESENTATIVE OF TARGET POP - 14DIS OF RSSAAMPLE MAY NOT BE REPRESENTATIVE OF ALL POP - memebers of t pop have = chance of being selcted - people wit similar characteristics may be selcted - decreases external pop val of the study - not possible to generalise to t pop
TIME CONSUMING (if t pop is big)- time consuming to identify and write down the names of all members of t pop - takes a lot of money and time (random sampling is so difficult that non-random methods are often used by researcher)
SAMPLE MAY NOT TRULY BE RANDOM- some of those chosen do not consent to take part (researcher must select more participants by doing further random sample of remaining members of t pop- time consuming, may mean sample only represents certain members of the target pop (those willing to engage in research) - reduces external pop validity of the study) - 15SYSTEMATIC samplingresearcher obtains the names of everyone in target pop . selects every NTH member to use in sample n stands for the number that the researcher would decide WHEN designing the study)
ADV - NO BIAS -researcher has no control over who is every nth number - can't influence who takes part - can't select participants who are likely to produce results that support their hypothesis (increases val)
SAMPLE IS LIKELY TO BE REPRESNTATIVE OF THE TARGET POP - sample selected from entire target pop - likely all diff types of people that make up the target pop will be represented in the sample - increases val - possible to generalise the results to target pop - (NOT GURANTEED A SMAPLE THAT IS REPRESENTATIVE OF THE TAGET POP) - 16disSAMPLE MAY NOT BE REPRESENTATIVE OF THE TARGET POP - by selecting every nth member of T pop , researcher may by chance select people with similar characteristics (e.g. all males) - would decrease external pop val - not possible to generalise results to target pop)
TIME CONSUMING (if target P is too high) - time consuming to identify and write down names of all members of the target pop) - takes a lot of time and money
MAY NOT SELCT WILLING PARTCIPANTS - not all participants selected are willing to take part in the research - researcher may have to engage un further systematic sample to select more participants- time consuming, sample only represents certain types of people (those most willing to engage = in research) - reduces external pop val of the study - 17STRATIFIED samplingsample mirrors the target pop - proportions of each sub group are the same in the target pop and the sample
- 18to gather stratified sample, the researcher...1. identifies different subgroups in target pop
2. calculates no. of each subgroup required for the sample (based on the proportions in target pop)
3. writes names of every member of the target pop on a piece of paper, puts them in diff containers according to subgroup they belong to
4. draw out the required no. of names for each subgroup - 19ADV and DIS of stratified samplingNo RESERACHER BIAS: random selection of each subgroup- researcher can't influence who takes part, can't select participants who are likely to produce results that will support their hypothesis - increases Val
SAMPLE LIKELY TO BE REPRESNTATIVE OF TARGET POP -sampling methods aim to create a sample that mirrors the characteristics of the target pop - highly likely to represent all diff types of people in target pop- increases external pop Val - generalise results to target pop - IMPOSSIBLE TO ACCOUNT ALL OF THE MANY WAYS THAT PEOPLE ARE DIFFERENT SO THE SAMPLE MAY NOT BE FULLY REPRESENTATIVE OF THE TARGET POP IN ALL WAYS
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dis - time consuming to identify all diff subgroups especially if target pop is big and diverse (many diff characteristics to consider when creating subgroups) - takes a lot of time and money
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- A level Psychology FlashCards sobre 3] pop and sample & sampling techniques + implications , criado por Ellaine Wahome em 23-11-2022.
- Criado por
- Ellaine Wahome
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