#3 Step 3 & 4: Measurement Reliability + Sampling

Question 1

What is reliability in measurement?

Answer 1

The extent to which a measurement is consistent

Question 2

What is reliability across time + procedures to solve it?

Answer 2

We may not be able to get an identical score when we make measurements on the same person (because of the participant and environmental factors)

1. Test-Retest Reliability: the extent to which scores on the same measured variable correlate with each other on the same measurement at 2 given times
2. Parallel-Forms Reliability: the extent to which scores on similar, but not identical, measures administered at 2 different times correlate with one another

Question 3

What is reliability across raters? How to improve inter-rater reliability?

Answer 3

We typically rely on 1 or more raters to quantify characteristics or behaviours.

• 1 rater: self-report
• more than 1 rater: observers, and could lead to random error (e.g. bias, mood etc)

Inter-rater reliability: extent to which ratings of one or more judge correlate

• train the raters
• revise scale to standardise
• have more raters to get aggregate

Question 4

What is reliability across items and how to solve?

Answer 4

When the measurement has more than one item, there must be internal consistency (the extent to which items on a scale correlate with one another, thus measuring true score rather than a random error)

1. split-half reliability
2. Cronbach’s Coefficient Alpha

Question 5

What are the 2 types of sampling?

Answer 5

1. Probability sampling: the entire population is known, and the sampling process occurs by a random process based on probabilities
2. Non-probability: the population is not completely known, and the method is based on common-sense or ease, with an effort to make representation

Question 6

Types of probability sampling

Answer 6

1. Random sampling
2. Systematic sampling
3. Stratified random sampling
4. Proportionate stratified sampling
5. Cluster sampling

Question 7

Types of non-probability sampling

Answer 7

1. Convenience sampling
   - based on availability and willingness
2. Quota sampling
   - identifying subgroup to be selected then establishing quotes (e.g. race)

Question 8

Ethics: Belmont Report

Answer 8

1. Respect for persons
2. Beneficence
3. Justice

Question 9

Ethics: 4 Keys

Answer 9

1. No harm
2. Confidentiality
3. Informed consent
4. Debriefing