INRS 7311 Learning Unit 4 Sampling and Data Collection Theme 1 Population and Sampling Flashcards
Identify the population of a research study 3 marks
- The whole group of people/entities from which the info is required or gathered
- This group is specified using research questions(outlines where data will come from )
- All members in a population must have one characteristic linking them to the research
Explain the concept of population parameters 3 marks
- Shared characteristics of the entire population chosen .
* Eg nature , size , etc
Identify different units of analysis3 marks
- Smallest possible units that can be investigated or researched .
- EG people , groups , organisations etc
Discuss key considerations in identifying a population 6-8 marks
- Determine the nature of the population by seeing whether research questions are best asked by turning to people , groups , organisation etc .
- Once you have the nature of the population , determine the common characteristics between the units of analysis
- Using this info the population can now be defined .
- Target and accessible population can now be distinguished between .
Distinguish between target and accessible population 4 marks
- Target audience = Any and everyone that falls into the characteristics outlined by the study .
- Accessible = Only population included in the study .
Describe sampling and different sampling methods . 4 marks
- Sampling is cutting the population who have the required characteristics down to a reasonable size .
- A sample is subset of the population that suitably represent the population
Explain what is meant by a representative sample 3 marks
- Shares the characteristics of the general population .
* Questions to this population should be the same standard/style as if the whole population was included .
Explain a sampling error 4 marks
- The extent to which we can generalize the findings to the rest of the population .
- Indication of how confident that a certain part of the population will provide similar result to the sample .
Explain a sampling frame 3 marks
- A full list of elements of the population .
* eg : phonebook , staff list , mailing list etc
Discuss the aspects to consider when choosing a sampling method 5 marks
- Sample is a subset of the population
- Sampling frame is a list of elements included in the population
- Final sample must have same relevant characteristics of the whole population to be a fair representation
Distinguish between probability and non probability sampling methods . 10 marks
- Probability sampling : has each unit in the population had the equal chance to be in the sample . This method is preferred in quantitative studies .Leads to a sample that : fits in with research parameters , is randomly drawn , requires little influence from the research , and leads to generalisable findings
- Non-probability sampling : Done when it is impossible to determine entire population or difficult to gain access to it . The chance to be in the sample isn’t equal. Used in qualitative research . Sample drawn is : in line with research parameters , all aspects of population aren’t available to access , when getting a representative sample isn’t the goal of the study .
List probability sampling methods
Simple random sampling , systematic sampling stratified sampling , multi-stage cluster sampling
Explain random sampling 3 marks
- Each unit has an equal chance of being picked to be in the sample “ drawn from a hat “ .
- Helps remove researcher bias
Explain systematic sampling . 4 marks
- The sampling frame is used to list all the units of the population .
- An interval is set ( eg every 5 units) then that unit is put into the sample . eg for a population of 100 to get a sample size of 20 units , the interval might be 5 for instance .
Explain Stratified sampling 4 marks
- Split the population into strata ( groups that have similar characteristics within the same population)
- Simple random sampling or systematic is then used to draw sample
Explain multi stage cluster sampling 3 marks
- Done when the sample frame is too big and/or widespread
* Frame is split into cluster at least twice , from which a random draw is done for the final sample .
List the non-probability sampling methods
*Accidental , Convenience sampling , purposive , Quota , Snowball , Volunteer
Explain accidental sampling 3 marks
- Sample isn’t taken from a frame , but chosen because they were in the right place at the right time .
- These results cannot be generalised , as the sample was chosen at random
Explain convience sampling 4 marks
*Sample is taken from units that are the most easily accessible . Different from accidental sampling in that the researcher is likely in regular contact with the units before the research begins , which is what makes them convienience in the first place .
Explain purposive sampling 5 marks
- Use of a set list of characteristics to choose our sample .
- Researcher then handpicks units that fit these characteristics from the population .
- Helpful as this ensures perfect sampling unit compliance .
Explain Quota sampling 5 marks
- Similar to purposive sampling .
- Differs in that the ratio of units picked for the final sample reflects the unit ratio as the population .
- eg if red sweets outnumber blue sweets two to one , the final sample of sweets will reflect this .
Explain snowball sampling 3 marks
- Often used in qualitiative research
- Based on referrals .
- Researcher gets in contact with one unit who fits characteristics . You then get them to put you in contact with other units they think fit your characteristics
Explain volunteer sampling 5 marks
- Units volunteer themselves for the research
- Leads to many errors
- People only will answer Q’s when either the chance to get something in return or voice their unhappiness at something .
- If not for either of those reasons , then volunteers subtly give answers they think are desired rather than being honest .
