Lecture 2

Question 1

What is the purpose of psychological measurements?

Answer 1

Mathematical/ statistical application measuring psychological attributes thought to be important in describing/ understanding normal/ abnormal expression of personality/ intelligence

Question 2

What are the main purposes of psychometrics?

Answer 2

• Allows for measurement of hidden psychological attributes- indirect, normally only see expressions of attributes ie angry
• Making important decisions about individuals- psychopathology, employment, education
• Fairest/ best/ most economical method

Question 3

What are limitations of psychometrics?

Answer 3

• Precision and accuracy
• Highly specialised
• Can be controversial

Question 4

Why is the high level of specialty a limitation?

Answer 4

• Focus- can’t measure the whole self, have to choose a subclass ie personality, then anxiety
• Identification and minimisation of inherent errors- unknown variance- can’t capture entire space of depression, therefore errors in tests such as DASS
• Administration and interpretation- will be interpreted differently by different psychologists

Question 5

Why is the high level of specialty a limitation?

Answer 5

• Focus- can’t measure the whole self, have to choose a subclass ie personality, then anxiety
• Identification and minimisation of inherent errors- unknown variance- can’t capture entire space of depression, therefore errors in tests such as DASS
• Administration and interpretation- will be interpreted differently by different psychologists

Question 6

What is a sample?

Answer 6

• Process of selecting to observe some part of a target pop in order to estimate some characteristics of pop

Question 7

What is a population?

Answer 7

Total cohort of interest

Question 8

What are sample qualities?

Answer 8

• Representativeness
• Biasedness
• Response rate/ non-respondent/ dropouts/ volunteers
• Instability of psych attributes/ sample size

Question 9

What are biases in sampling?

Answer 9

• Degree of systematic error present in sample

- Can create under/ over estimates of pop values

Question 10

What are examples of instability in psych attributes?

Answer 10

• Degree of homogeneity in members of pop
• Fluctuate/ drift through lifespan, change radically
• Will come up as error
• Ie Christian-based society- don’t sample around Christmas

Question 11

What are types of sampling?

Answer 11

-Probability (random) sampling
• Every pop unit has a known, not necessarily equal, chance of being included
•One can infer a known degree of confidence and error (bias), accurate, precise, and meaningful estimates of the characteristics of interest to the target pop
o Eg: simple (quasi-) random, systematic random, stratified, cluster

• Non- probability- do not take into account elements of chance, findings shouldnt be used to generate inferences about pop

Question 12

What are the two types of scoring?

Answer 12

o Objective
• Eg standardised questionnaires, blood tests
o Subjective: assessors’ judgment
• Eg vignette and projective tests
o Best to use both
• Don’t often
• Subjective takes a long time
• So tend to use objective