Scientific Measurement

Theory

a particular conception or view of a phenomenon

a system of rules or principles about how something works

Hypothesis

proposed explanation for a particular fact or event

Data

a collection of facts about an object or phenomenon under study

requires measurement procedures and systematic recordings

Variables

phenomenon you are trying to measure in some way

Independent variables

factors you are manipulating as the researcher

the difference between experimental groups

Dependent variable

the variable being tested and measured as the result

Causal relationship

a relationship where one variable directly influences another; changing one parameter (independent) will lead to a change in an outcome measure (dependent variable)

Direct relationship

as one goes up, so does the other

Inverse relationship

as one variable goes up, the other goes down

Non-causal relationship

no cause-and-effect relationship between variables

confounding variable

as outside factor that relates the independent variable to the dependent variable when they are not causally related to each other directly

Hawthorne Effect

subjects behave differently when they know they are being watched/tested

Rosenthal Effect

self-fulfilling prophecy where the research’s expectations influences their interpretation of the results

Sources of error in equipment

calibration, sensitive enough to detect change, human error in applying, can lead to systematic error in data

Intra-subject reliability

variations within a given subject’s performance

Intra-rater reliability

variations within a given tester

Inter-rater reliability

variations between testers

Validity

the extent to which the test measures what the researcher intends to measure

Acquisition

early learning practice trials, typically graphed as a performance curve of trials within a session, does not necessarily represent a permanent change in capacity for skilled movement

Retention

the persistence of original learning over a period of no practice (better than original baseline)

Transfer tests

how effectively one can carry over learning of a skill from one condition to another, measures learning

Constant error

the average magnitude and direction of error relative to the target goal (bigger # = farther away from the goal)

Variable error

the average magnitude and direction of error relative to the performance mean (are you consistent to yourself?)

Total Variability

a combination of VE and CE that measures overall accuracy as it encompasses both consistency and success in achieving the target goal