validity reliability Flashcards
defining your population and representation
how the study reflects a larger population
how does sampling bias occur
Occurs when certain subgroups are overrepresented or underrepresented. * Range of Factors: Socioeconomic status, Geographic location, Occupation, On-field position in sports, Fitness Level, Age, Experience
What are descriptive statistics
provide a summary of the basic features of the Data. ecamples, age height mass competition levels,
what are the two key elements of descriptive statistics
mean= represents the average value
standard deviation= hoe spread out the values are around the mean
What is reliability
Refers to the reproducibility or consistency of a measurement when it is repeated.
INTRA RATER RELIABILITY
how consitent an individual is at measuring a constant phenomanom.
INTER RATER RELIABILITY
How consistent different individuals are at measuring the same phenomenon/test
INSTRUMENTAL RELIABILITY
How consistent an instrument is in measuring the same phenomenon/test
What is the common measurement
Several statistical measures can be used to quantify the consistency of the data.
the correlation co efficient
Pearsons (r) is common
* Closer to 1 or -1 the closer the relationship, 0 is no relationship
co efficient of variation
lower percentage of variation the better
intraclass correlation co efficient
Essentially a reliability index. Kappa is
common in inter rater analysis
standard error of measurement
Closer to 1 the lower the error eg. “the SEM for intra rater test-retest reliability was 0.98”
What is validity
How sound is the research, in aspects of designs and methods , findings truly represent the value you want to measure
Construct validity
does the test measure the concept it intends to measure
content validity
is the test fully representatie of what it entails to measure
What is internal validity
Refers to the degree to which the results of a study accurately reflect the relationship between the variables being studied
* High internal validity means that the study is well-constructed, and any observed effects are likely due to the variables being studied rather than other confounding factors.
* Common Threats to Internal Validity: * Population
* Choice of participants can affect internal validity if the sample is not representative of the population being studied.
* Data Collection
* Method of data collection can also introduce bias or error
* Equipment
* Reliable and well-calibrated equipment is essential for gathering accurate data.
Instrument validity
Measures what it is supposed to.
* Often in comparison to the gold standard at the time (criterion variable).
External validity
extent to which you can generalize your findings to other contexts , cannot be applied to other environments or groups.
eg weightloss study in japan not applicable to ireland
or it is not applicable in the real world due to cost or demands
Face Validity
Does the method measure what it is intended to measure? commonly subjected by subject exports
