1 - Measurements Flashcards
define measurement
assigning of scores to represent a characteristic
measurement quantification allows researchers to?
ask if there is a mathematical relationship present
Psychological measurement is known as
psychometrics
are three categories of measures.
what are they?
- Self-report measures e.g. Likert scales
- Behavioural measures e.g. naturalistic observations
- Physiological measures e.g. heart rate
There are four scales of measurement with increasing amounts of information in each level.
what are they?
- Identity or qualitative difference
- Magnitude or rank order
- Equal intervals
- True or absolute zero
what are constructs
variables that cannot as easily be assessed/measured
Conceptual definitions describe ?
the behaviours and internal processes that make up the construct
give 2 characteristics of the interval scale
- Adds equal intervals (necessary for most statistical analyses)
- Arbitrary zero point -the value of zero has no real meaning- (e.g., z scores - a statistical measurement of a score’s relationship to the mean in a group of scores)
give 5 characteristics of the nominal scale
- Simplest scale with only qualitative difference or identity
- Mutually exclusive ‘name’ categories
- Words as labels (e.g., male/female)
- Numbers used as labels (e.g., sports jerseys)
- Not ordered.
give 4 characteristics of the ordinal scale
Adds rank order or magnitude (e.g., rank class by height)
MORE information than nominal
But we do NOT know what the difference is between the ranks (e.g., differences between 1 and 2 versus between 2 and 3 like height, time taken to finish a race)
give 3 qualities of the ratio scale
- Adds absolute zero
- Absence of the quality (e.g., money in my bank account)
- Allows for legitimate ratios (e.g., twice as heavy)
NOIR: nominal (1)
category labels
NOIR: ordinal (2)
category labels
rank order
NOIR: interval
category labels
rank order
equal intervals
NOIR: ratio
category labels
rank order
equal intervals
true zero
define reliability
reliability is consistency (getting (roughly) the same score when repeatedly measured)
define validity
Validity: ‘actually’ measuring what you intended to measure.
data can be reliable and not valid but cannot be
valid and not reliable
what is internal consistency?
reliability can also be assessed at one point in time
If observations are consistent, then you have?
inter-rater reliability
define face validity
the content of the measure appears to reflect the construct being measured
(Appears to be measuring what it claims to measure)
define content validity
the content of the measure is linked to the universe of content that defines the construct.
(Does it tap into all the important aspects of the constructs)
define predictive validity
scores on the measure predict behaviour on a criterion measured at a time in the future
(Does the measure actually predict behaviour)
define concurrent validity
scores on the measure are related to a criterion measured at the same time
(Relationship between a measure and a behaviour occurring at the same time OR whether two or more groups behave in expected ways )
