Clinical Methods Flashcards
Clinical Neuropsychology
specialty domain in psychology which examines the relationship between behavior and brain fx in the domains of cognition, motor, sensory, and emotional fx
Fixed battery assessments
set of neuropsychological tests defined within a structure or conceptual framework, give in their entirety
Neuropsychological process assessment
AKA Boston Process Approach, framework that derives insights not only from final test output, but also from the process of completing cognitive tasks
Validity
Degree to which a test measures what it proports to measure
Predictive validity
degree to which test scores accurately predict scores on a criterion measure
Criterion validity
estimate of the extent to which a measure agrees with a gold standard
Criterion validity is limited by the test’s
standard deviation
Content validity
how well an instrument covers all relevant parts of the construct it aims to measure
Sensitivity
measure of validity, how accurate the screening test is in identifying disease it people who really have the disease, E.g., a metal detector that detects all pieces of metal at the beach
Specificity
ability to designate an individual who does not have a disease as negative
E.g., a pregnancy test needs to have high specificity to detect people who are not pregnant
E.g., metal detector does not detect pieces of plastic, etc.
Reliability
degree to which a test is consistent and stable in measuring what it is intended to measure, Consistent within itself and across time
As reliability decreases, what increases?
Standard error of measurement
Reliability coefficient
Value ranges from 0-1, provides estimate of the amount of obtained score variance that is due to true variance rather than error
AUC of a ROC curve reveals
the overall accuracy of a test (validity), plot of sensitivity and specificity
Positive Likelihood Ratio (LR+)
probability that a positive test would be expected in a patient divided by the probability that a positive test would be expected in a patient without the disease
True positive / false positive
Positive predictive power
probability that a person has a disease or condition given a positive test result
Sensitivity!
Negative predictive power
probability that a person does not have a disease or condition given a negative test result
Specificity!
Type I Error
False positive, determines something is true when it is actually false (too sensitive)
Type II Error
False negative, wrongly indicates that someone does not have the condition when they do (too specific)
Error variance (variability)
score that is produced by extraneous factors not attributable to the independent variable or other controlled experimental manipulations
Amount of variance explained by other factors
Measurement errors
observational errors, differences between actual response and the measured response value
Practice effects
any change or improvement that results from practice or repetition of task items
Regression to the mean
stat phenomenon, natural variation in repeated data look like real change, unusually large or small measurements tend to be followed by measurements closer to the mean
Hit rate
the percentage of cases in which a test accurately predicts success or failure on those people selected and rejected, Goal is to maximize hits and minimize misses (means test is is able to differentiate between people on a characteristic = sensitive and specific)
Base rate
percentage of the population that have the characteristic
Standard deviation
average amount of variability in the dataset
On average, how far each value lies from the mean
Standard Error of Measurement (SEM)
estimates how repeated measures of a person on the same instrument tend to be distributed around their “true” score, inversely related to reliability
Statistical significance
measure of the probability of the null hypothesis being true compared to the acceptable level of uncertainty regarding the true answer, Statistical likelihood of a score
Percentiles
value that divides a set of observations into 100 equal parts = proportion of values that a specific value is greater than or equal to
T-test
statistical test that compares the means of two samples
ANOVA
statistical formula used to compare variances across the means of different groups
ANCOVA
analysis of covariance in combination of an ANOVA and regression analysis
Examines influence of independent variable on a dependent variable while removing the effect of the covariate factor
Item difficulty index
for items with one correct alternative worth a single point, the item difficulty is simply the percentage of students who answer an item correctly
Reliability is important ethically so that
Test is less affected by internal rate conditions that are unimportant to the measurement purpose or test situation’s conditions
