LECTURE 6

Question 1

What is a sample?

Answer 1

A subgroup of the population used in a study.

Question 2

What is a population in research?

Answer 2

The entire group of interest, such as all psychology students.

Question 3

What is a sampling frame?

Answer 3

The group from which a sample is chosen, usually a subset of the population.

Question 4

What is representativeness in sampling?

Answer 4

The extent to which the sample accurately reflects the population.

Question 5

What is selection bias?

Answer 5

Bias that occurs when the sample is not representative of the population.

Question 6

What are types of selection bias?

Answer 6

Sampling bias, nonresponse/volunteer bias, and attrition bias

Question 7

What is sampling bias?

Answer 7

Bias due to an unrepresentative sampling frame.

Question 8

What is volunteer bias?

Answer 8

Bias when volunteers differ significantly from non-volunteers.

Question 9

What is attrition bias?

Answer 9

Bias when participants who drop out are different from those who complete the study.

Question 10

What is random sampling?

Answer 10

Every member of the sampling frame has an equal probability of being chosen.

Question 11

What is systematic random sampling?

Answer 11

Selecting participants at fixed intervals from a randomized starting point.

Question 12

What is stratified sampling?

Answer 12

Dividing the population into subgroups and sampling randomly within each subgroup.

Question 13

What is cluster sampling?

Answer 13

Dividing the population into clusters, then randomly selecting clusters to study.

Question 14

What is opportunity/convenience sampling?

Answer 14

Selecting participants who are readily available.

Question 15

What is purposive sampling?

Answer 15

Selecting participants based on specific characteristics or criteria.

Question 16

What is quota sampling?

Answer 16

Dividing the population into subgroups and filling quotas non-randomly.

Question 17

What is observation sampling?

Answer 17

Sampling behaviors in specific contexts, such as times, events, or situations.

Question 18

What is time sampling?

Answer 18

Observing behavior during specific time intervals.

Question 19

What is event sampling?

Answer 19

Observing specific events within a timeframe.

Question 20

What is situation sampling?

Answer 20

Observing behaviors in diverse locations or contexts to increase validity.

Question 21

What is ecological validity?

Answer 21

The extent to which study findings generalize to real-world situations.

Question 22

What is the sampling distribution?

Answer 22

A theoretical distribution of sample means if infinite samples were drawn from the population.

Question 23

What is sampling variability?

Answer 23

Differences in sample statistics due to the random selection of samples.

Question 24

What is the central limit theorem?

Answer 24

The sampling distribution of the mean is always normally distributed, regardless of population distribution.

Question 25

What is the standard error (SE)?

Answer 25

The standard deviation of the sampling distribution, indicating variability of sample means.

Question 26

How does sample size affect the standard error?

Answer 26

Larger sample sizes reduce the standard error.

Question 27

What is a confidence interval?

Answer 27

A range around the sample mean within which the population mean likely falls (e.g., 95% confidence).

Question 28

How is a confidence interval calculated?

Answer 28

By adding and subtracting 1.96 standard errors from the sample mean for a 95% confidence level.

Question 29

Why is the value 1.96 used in confidence intervals?

Answer 29

It corresponds to 95% of values in a standard normal distribution.

Question 30

What is a z-score?

Answer 30

A measure of how many standard deviations a value is from the mean of its distribution.

Question 31

How is a z-score calculated?

Answer 31

Subtract the mean from the value and divide by the standard deviation.

Question 32

What is the standard normal distribution?

Answer 32

A normal distribution with a mean of 0 and a standard deviation of 1.

Question 33

How can z-scores compare different scales?

Answer 33

By standardizing scores from different distributions, making them comparable.

Question 34

What is the relationship between confidence intervals and sample size?

Answer 34

Smaller sample sizes produce wider confidence intervals.

Question 35

What is the expected value in sampling?

Answer 35

The mean of the sampling distribution, equal to the population mean.

Question 36

Why are large samples preferred in inferential statistics?

Answer 36

They reduce sampling variability and provide more accurate estimates of the population.

Question 37

What is the main takeaway about sampling methods?

Answer 37

Proper sampling ensures representativeness and improves the validity of inferences.

Question 38

How can sampling bias affect study results?

Answer 38

It can lead to findings that are not generalizable to the target population.