Sampling

Question 1

What is a population?

Answer 1

Entire group of people of interest
e.g all psychology students

Question 2

What is a sample?

Answer 2

Subgroup of the population
e.g psychology students in one class

Question 3

What is a sampling frame?

Answer 3

group from which the sample is chosen from
e.g psychology students willing to participate and be tested in a lab

Question 4

What is representativeness?

Answer 4

the extent of similarity between sample and population

Question 5

What is selection bias?

Answer 5

occurs when the sample is not representative
3 types

Question 6

What are the 3 types of selection bias?

Answer 6

sampling bias
volunteer bias
attrition bias

Question 7

What is sampling bias?

Answer 7

occurs when sampling frame is not representative

Question 8

What is volunteer bias?

Answer 8

people who participate in studies are different from those that don’t participate

Question 9

What is attrition bias?

Answer 9

ppts who drop out of study are different to those who don’t

Question 10

What are the 2 types of sampling methods?

Answer 10

probability (random selection)
non-probability (no random selection)

Question 11

What are examples of probability sampling?

Answer 11

simple random sampling
systematic random sampling (every nth person)
stratified sampling
cluster probability sampling

Question 12

What are examples of non-probability sampling?

Answer 12

opportunity (convenience) sampling
purposive sampling
Quota sampling

Question 13

What is purposive sampling?

Answer 13

ppts are included and excluded based on researchers judgement

Question 14

What is Quota sampling?

Answer 14

when population is divided into subgroups
ppts are selected to fill a quota (non-random selection)

Question 15

What are the 3 observation sampling methods?

Answer 15

time
event
situational

Question 16

What is time sampling?

Answer 16

random - note down any behaviours that happen after diff amount of times
systematic - note down any behaviours that happen after set time e.g every 5mins

Question 17

What is event sampling?

Answer 17

define behaviours then note them down every time they are observed

Question 18

What is situational sampling?

Answer 18

when you observe behaviours in diff locations
increases external validity

Question 19

What is sampling variability?

Answer 19

each time we draw a sample from same population we make different observation and statistics are also different

Question 20

What is sampling distribution?

Answer 20

A normal distribution with a mean (expected value) and a S.D (standard error)

Question 21

What impression does confidence intervals give?

Answer 21

how close the sample mean is to the population mean

Question 22

What do you call a distribution with a mean of 0 and a S.D of 1?

Answer 22

either a standard normal distribution or z distribution

Question 23

What do Z-scores show?

Answer 23

deviation from the mean in S.Ds

Question 24

How to work out Z-transformation

Answer 24

for every value we subtract the mean of the distribution and divide by the S.D