Psychometrics Flashcards
1
Q
What is the Individual Differences Approach?
A
ID is a subclass of Differential Psychology ID seeks to understand and establish psychological dimensions that apply to everyone, yet allow for or create individual differences Attempts to discover what makes a person that person
2
Q
What are the assumptions of ID?
A
- Assumes a connection between normal and abnormal expression of traits
- Assumes intelligence and personality are fluid not static
3
Q
What are the 2 major conceptual focus areas of ID?
A
- The Structural Model (the ‘what’):
- How individuals differ, what is the structure of personality/intelligence - What are the societal, cultural, psychophysiological, experiential differences
- The Process (Dynamics) Model (the ‘why’):
- When, why and where people differ, the functional factors of the differences - Causes and consequences of differences
4
Q
What is the purpose of tests in ID?
A
- Tests in ID are defined as “systematic applications of a few relatively simple principles which attempt to measure personal psychological attributes”
- Allow for indirect assessment of hidden psychological attributes
- Used to make decisions around people (treatment, education etc)
5
Q
What are some of the general limitations of psychological testing?
A
- Most important: Minimisation of Error (unaccounted variance) -
- Precision/accuracy - High specialisation: focused not exhaustive questions -
- Administration and interpretation limitations
- Ethical Limitations: tests are required to meet ethical standards
- respectful treatment
- informed consent,
- privacy,
- confidentiality,
- withdrawal from testing
6
Q
What are some of the defining characteristics of psychological tests?
A
- A psychological test is a ‘sample of behaviours, attitudes, thoughts and feelings’.
- Value is largely determined by representativeness, biasedness, error, sample size, stability of attributes, response rate
- Sampling is obtained through standardised conditions
- random sampling: simple, systemic, cluster
- non-random sampling: convenience, quota
- Involves established rules for scoring and data collection
- Objective (standardised questionaiires, blood tests), vs Subjective (interview)
7
Q
What are some chief concerns regarding the interpretations of psychological test results?
A
- Are attributes real?
- cultural biases, administration biases, faking, framing and research biases
- Are attributes important?
- difference between statistical and practical importanc
- Do tests help or hinder?
- issue of labelling
8
Q
What is a psychological measurement (and its limitations)?
A
- The process of assigning numbers to a person such that some attributes of the person are accurately represented
- Assumptions & Limitations
- Personality exists and is real,
- Personality can be represented by numbers (imperfectly),
- Individual differences have relative stability (predictive variability)
- cannot measure whole person,
- assesses a single attribute
9
Q
What are the four basic scale types (NOIR)?
A
-
Nominal (categorical): an attribute is nominated an abitrary numerical value
- Dichotomous: Yes[1] No [0]
- Polytomous: Answer A[0] B[1] C[2]
-
Ordinal (categorical): attributes are rank ordered on an underlying quality. Distances between points unknown.
- Balanced: neutral scale point in the middle
- Unbalanced: either no neutral point or non middle neutral point
- eg. Likert scale: 5 point agreement scale (balanced)
- Interval (numerical): attribute scaled on even intervals (uncommon) eg temperature
- Ratio (numerical):ratios between measured numbers = ratios between desired attributes. eg reaction time
10
Q
What is scale transformation and standardisation? How and Why?
A
- Why transform or standardise?
- raw scores often insufficient for comparison (different scales/versions)
- standardisation -> creation of universal indexes
- generation of population norms (indicate population distribution, norm based interpretation
- Common transformations
- z-scores: standard deviations
- t-scores: z-score transformation
- area transformations: quartiles, percentiles
- stanines: standard nines 1-9 point scale
11
Q
What is validity and some of its related issues?
A
- What is validity?
- The degree to which a test measures what it claims to measure
- The appropriateness of test-scores and their interpretations
- The degree to which measurements are a true representation
- Level of logical and statistical biases in tests and conclusions
- Some issues with validity
- Psychological constructs are abstract and hidden
- Declaring an instrument is either valid or invalid is unjustifiable in absolute sense
- What is meaningful and useful in psychological testing?
12
Q
What is content validity?
A
- Whether scores represent the content area; scores should be whole or unbiased representation of the domain
- issues:
- bias, sampling bias, cluster bias, *systematic error* (accuracy bias)
- ceiling/floor effects
- expert judges
13
Q
What is Criterion related validity?
A
- The degree to which a test correlates with one or more parallel outcomes
Correlation is called the validity coefficient - Two types:
1. Concurrent: criterion in present i.e. long form v short form
2. Predictive: criterion in future
14
Q
What is Construct (factoral) validity?
A
- The degree to which assessed constructs possess a sane theoretical foundation which is operationalised through measureable descriptors
15
Q
What is convergent and disciminant validity?
A
- Convergent: High level of correlation between items that make up the same constructs or related constructs
- Divergent: Low levels of correlation between items that make up unrelated concepts
