Quantitative Data Analysis and Interpretation Flashcards
Explain what goodness of fit is.
it looks at how well the pieces fit together; examines
purpose, design, research question(s) or hypothesis, conceptual and operational definitions, data collection method
How is data consistency achieved?
by measuring the data in the same manner for each subject
What must be developed in order to ensure intervention fidelity?
A data collection protocol that ensures data is measured in the same manner for each subject
assistants and co-investigators need to be trained into it to ensure consistency
What does Data Consistency ensure?
Interrator Reliability; consistency of observations
What is Interrater Reliability and how is it expressed?
it is the consistency of observations
Reflected as a coefficient kappa (Cohen’s Kappa)
What is intervention fidelity?
consistency in data collection
List some data collection strategies
Physiological or biological measurements
observational methods
interviews (open or closed ended)
Questionaires
Records or available data
ex hospital records, historical documents, audio or video tapes
What are the four important things that must be present in observational methods?
1) observations undertaken are consistent with the study’s objectives and theoretical framework
2) Standardized and systematic plan for observation and recording of data
3) training data collectors
4) All observations checkeed and controlled
give some examples of measurement tools
pain scales
CAM scores
Intelligence testing
Anxiety scales
What is the term that means evaluating the measurement tool?
Psychometrics
What does reliability of a measurement tool mean?
it means the CONSISTENCY with which the instrument measures the concept of interest
What are the three aspects of reliability of a measurement tool?
STABILITY
HOMOGENEITY / INTERNAL CONSISTENCY
EQUIVALENCE / INTERRATER RELIABILITY; Cohen’s kappa
Describe what stability of a measurement tool means.
it is the test-retest reliability.
ie. how consistent it remains over time
Describe what homogeneity/internal consistency is
it is the extent to which items within a scale reflect or measure the same concept
What is used to measure homogeneity/internal consistency and what is the acceptable value?
Chronbach’s alpha
want 0.80 or greater
0.70 might be acceptable if tool was designed exclusively for the study
What is another term for interrater reliability?
equivalence
What are the two concepts that psychometrics examine?
Reliability and Validity
Describe what control is
it is measures that the researchers take to make the conditions uniform to avoid EXTRANEOUS variables from influencing the dependent variable
Describe how control of the treatment might be obtained.
Make a detailed description of the treatments
Use strategies to ensure consistency in implementation;
Same nurse does intervention, uses same equipment, at the same time, in the sae sequence
What is the impact of variations in treatment on the study?
it reduces effect size and internal validity
effect size; strength of the phenomenon
What are 4 strategies that can be implemented to control the extraneous variables?
1) homogenous sampling
2) data consistency
3) Random selection and randomization
4) Manipulation of the independent variable
Describe what validity means in terms of psychometrics
the extent to which an instrument actually measures or reflects the abstract construct
ie accuracy
How can validity of a measurement tool be established (psychometrics)
through expert opinions / panels
and through comparison to other scales or events
What is internal validity of a study
the extent to which the study findings are true rather than the result of extraneous variables
Factors from WITHIN the study design
What is external validity of a study?
the extent to which study findings can be generalized beyond the sample used in the study
Can you apply findings OUTSIDE the study
What are 6 things that can threat internal validity. Describe each
1) maturation: developmental changes that occur over time
2) history: events that occur outside of the study
3) Mortality: unequal rates of attrition
4) Instrumentations: any changes
5) Testing: effect of testing and retesting
6) Selection bias: may have unmeasured attributes that create differences in groups
What are some threats to external vailidity (3)
1) Selection Effects: who is in the study
2) Reactive Effects: Hawthorne effect (how behaviour changes as a result of awareness of observation)
3) Measurement Effects
What is the Rosenthal Effect (also known as the Pygmalion Effect)?
It is a phenomenon where behaviours change based on researcher’s expectations
What can be done to reduce the bias from the Rosenthal Effect?
Double blind experiment
Describe what the Halo Effect is.
It is a phenomenon where a participant can score better based on past scores/assessments
ex: a student who gets good grades might get a good grade on a substandard work based on past performance.
