Psychometric Properties of Assessment - Coggle Diagram
Psychometric Properties of Assessment
Direct observation approaches
Behaviour you are attempting to explain: specific, clearly defined, observable, measurable, reliable definition
what do you want to record?
who records? where does the recording take place?
Consequences - what reductions occured? What stopped? What increases occured?
Multiple baseline methods of tracking a problem
: does a subsequent completion result in the same score if all other variables stay the same?
: do the items on each scale correlate with the total score for each scale?
how strongly are scores related within different groups of people?
Internal consistency (Cronbach's Alpha)
: how closely a related a set of items are as a group - acceptable range is above 0.70
: the tool correlates well with tools that measure the same/similar constructs
: the tool correlates poorly with tools that measure unrelated constructs
do scores correlate with an external 'gold standard' criterion eg criminal charges
Exploratory Factor Analysis:
focus on establishing an underlying factor structure
Confirmatory Factor Analysis
: used to verity a hypothesised factor structure
Testing Fit: how well the proposed model accounts for the correlation of all items
Root Mean Square Error of Approximation
Comparative Fit Index
Fit of the model
Standardised root mean square residual (SRMR)
: a good measure will show similar factor structures across different populations - do the psychometric properties stay the same across different groups