Research Flashcards
What is specificity?
TRUE NEGATIVE
—Tests ability to correctly identify those who DO NOT have the disease or condition
(SPIN)
What is sensitivity?
TRUE POSITIVE
-Tests ability to correctly identify those who DO have a condition
WHAT IS CORRELATION?
Attempts to determine whether a relationship exists between 2 or more quantifiable variables to what degree
-Describes/predicts relationships among variables w/o active manipulation of the variables
-***Degree of relationship is expressed as a correlation coefficient ranging from -1.00 to +1.00
A. If the correlation is near +1.00 the variables are positively correlated
B. If the correlation is near 0 then the variables are not related
C. If the correlation is near -1.00 then the variables are inversely related
What are examples of correlational research?
- Retrospective (past research)
- Prospective (present data)
- Descriptive (investigation of several variables at once; determines existing relationships among variables
- Predictive: develops predictive models
What are parametric tests?
-Testing is based on population parameters; includes INTERVAL OR RATIO data
-Types of tests: T TEST, TWO TAILED T TEST, ANOVA AND ANCOVA
What is a T-test?
Parametric test of significance used to compare 2 INDEPENDENT GROUPS created by random assignment and identify a difference at a selected probability level (ex: 0.05)
A) T test for independent samples: compares the difference between 2 IND groups (ex: does a hand splint help RA)
B) T test for paired samples: compares the difference between 2 matched samples (ex: does therapy improve function in siblings with autism?). Use One tailed T test and Two tailed T test for the paired samples
-You cannot use a T test to compare more than 2 means w/in a single sample; (ex: three modes of exercise are compared within a single sample)
What is a one tailed T test?
Based on a directional hypothesis; evaluates differences in data on only one end of a distribution, either negative or positive
Ex: pt’s who receive a certain trx exhibit better rehab outcomes than those who do not
What is a two tailed T test?
Based on a non directional hypothesis; evaluates differences in data on both + and - ends of a distribution; tests of significance are almost always 2 tailed. Ex: either group of pt’s (trx or control) may exhibit better rehab outcomes
What is ANOVA?
(Analysis of variance)
-a parametric test used to compare 3 or more independent trx groups or conditions at a selected probability level
A. Simple one way ANOVA: compares multiple groups on a single independent variable
-Ex: 3 sets of post test scores are compared from 3 categories of elderly (young, old elderly and old frail elderly)
B. Multi-factorial ANOVA: compares multiple groups on 2 or more IND variables
-Ex: 2 groups of injured patients (severe ankle sprain and moderate) and a control group are compared for muscle activation patterns and sensory perception in each limb
What is ANCOVA?
Analysis of covariance
-a parametric test used to compare 2 or more trx groups or conditions while also controlling for the effects of intervening variables
-Ex: 2 groups of subjects are compared on the basis of gait parameters using 2 different types of AD’s; subjects in one group are taller than subjects in the second group; height then becomes the covariate that must be controlled during statistical analysis
What are the non parametric tests?
No parametric: ordinal and nominal data
Tests: Chi-square
What is a nonparametric test?
Testing is not based on population parameters; includes ordinal or nominal data
-Used when parametric tests assumptions cannot be met
-Less powerful than parametric tests, more difficult to reject the null hypothesis
What is a Chi square test?
Tells the researcher whether the observed pattern, trait, or distribution is different than what would have been expected by chance alone
-Used in genetics or with population statistics
-Commonly used to rest relationships and differences between categorical variables
What is correlational statistics?
- Used to determine the relative strength of a relationship between two variables. Ex: compare progression of radiologically observed joint destruction in RA and its relationship to demographic variables (age), disease severity and exercise frequency
- Strength of relationships
A. Positive correlations range from 0 to 1: indicates that as variable X increases so does Y
-Good reliability >0.75
-Mod reliability: 0.50 to 0.75
-Poor reliability: <0.50
What is reliability?
-The degree to which an instrument measures a phenomenon accurately, dependably, time after time without variation
-Interrater
-Intrarater
-Test-retest reliability
-Split half reliability
What is interrater reliability?
Two or more independent raters can obtain the same rating for a given variable; the consistency of MULTIPLE raters
What is intrarater reliability?
The degree to which ONE rather can obtain the same rating for a given variable on multiple measurement trials, an individuals consistency of rating