CH 3 Flashcards
Quantification (definition)
Refers to the quantification of psychological information (i.e. numerical representation of psychological ‘objects’) usually for the purpose of making inferences based on mathematical/statistical techniques.
“assigning numbers to psychological events”
4 Measurement Scales
- Nominal: determination of equality
- Ordinal: + determination of order
- Interval: +determination of differences
- Ratio: + determination of ratios
Nominal Scales
- Numerals are assigned ONLY as labels or type numbers, and words or letters would save as well
- Satisfies determination of equality
- Stevens distinguished between 2 types- identification, (e.g. player 1,2,3,4) and classes (male, female)
Ordinal Scales
- “arises from the operation of rank-ordering”
- Satisfies determination of equality & determination of greater or less
- Most scales used in psychology are of the ordinal type (e.g. happiness scales, personality assessments, anxiety scales)
Interval Scales
- Satisfies determination og equality of intervals or differences (e.g. difference between 30 degrees celsius and 40 degrees celsius is ten degrees Celsius just as it between 0 and 10)
- “Quantitative in the ordinary sense of the word”
- Equal intervals, but the zero point is arbitrary
Ratio Scales
- Consist of “true zeros”- even though the zero values on some scales may never be produced
- Satisfies determination of equality & determination of greater or less & determination of equality of intervals or difference & determination of equality of ratios
- Most commonly found in psych when we count objects (e.g. number of offences committed in youth, weight of person)
Measurement scales vs Types of Variables
MS: refers to the properties of the scale that measures or ‘quantifies’ the attributes of interest
T.V: Refers to the type of variable that is taken to represent the attributes of interest
both: rely on the relations between the. values that a given variable can take on. So, they are linked. For example nominal and ordinal measurement scales are typically not associated with continuous variables
Types of Variables
Discrete Variables
(1) Nominal Variables (e.g. colour eyes)
(2) Dichotomous Variables (“yes” “no”)
Continuous Variables
(3) Pseudo-continuous-ordered categorical (e.g. likert scale)
(4) real continuous (time)
Joel Michelle’s Critique of Measurement in Psychology
- The Quantitive imperative
- Reductionism
- Measurement “instruments” in psych
The Quantitative Imperative
the Pythagorean notion that ALL attributes are quantitative. Since all attributes are taken to be quantitative, measurement is necessary to understanding all attributes
issue.
a) only ratio scales are true forms of measurement
b) in order for an attribute to be measurable, it must be quantitative
c) psychologists have not (probably can’t) prove that psychological attributes are quantitative
Reductionism
The view that the whole of a phenomena can be understood by studying its individual parts
problem: the “objects” under study in psychology exist within a complex sociocultural and historical context (they cannot be divorced from this context, but quantification forces you to do that–its reductionism)
- doesn’t do justice to the complex nature of psychology. . Are psychologists really understanding their “objects” of interest if they are studying them as if they are “acontextual”
Measurement “instruments” in psychology
The ‘measures’ we use in psychology to obtain information about psychological objects and events are not always very exact, or even generally measuring what we think they are like measures used in physics.
