KEY TERMS Flashcards
(70 cards)
Define Population (parameter)
Entire collection of events in which you are interested.
Eg. scores of all morphine injected mice or milk production of all cows in the country
Define Sample (statistics)
Set of actual observations; subset of a population
Define Statistics
Numerical values sumerizing sample data
Define Parameters
Numerical values sumerizing population data
Define Random Sample
A sample in which each member of a population has an equal chance of inclusion in the study.
Define Decision Tree
Graphical representation of decisions involved in the choice of statistical procedures
Define Measurement Data (quantitative data)
Data obtained by measuring objects or events
Categorical Data (frequency data & count data)
Data representing counts or number of the observations in each category
Define Measurement
The assignment of numbers to objects.
i.e. paw-lick latency as a measure of pain sensitivity, we are measuring sensitivity by assigning a number ( a time) to an object (a mouse) to assess the number of sensitivity of that mouse.
Define Scales of Measurement
Characteristics of relations among numbers assigned to objects.
Define Nominal Scale
Numbers used only to distinguish among objects.
i.e. numbers on jerseys have no meaning just convenient
label that distinguishes players on their positions from one another used for purpose of classification
Note: categorial data are often measured on a nominal scale b/c we merely assign category labels ( e.g. male or female same context group of different context group) to observe.
Define Ordinal Scale
Numbers used only to place objects in order. Orders ppl.,objects or events along some continuum. i.e. 1, 2, 3, 4, or number of changes rather than ranks.
Define Interval Scale
Scale on which equal intervals b/w objects represents equal differences - differences are meaningful.
i.e fahrenheit scale of temperature, in which a 10pt difference has the same meaning anywhere along the scale. Thus, the difference in temp. b/w 10F and 20F is the same as the difference b/w 80F and 90F
Define Ratio Scale
A scale with a true zero point- ratios are meaningful
i.e. ratio scale = common physical ones of length and volume.
Define Variables
Properties of objects or events that can take on different values.
i.e. hair colour, b/c it is a property of an object ( hair) that can take on different values ( brown, blonde, blk). Properties such has height, length and speed are variables for the same reason. Bib #’s position in race etc.
Define Discrete Variables
Variables that take on a small set of possible values.
(i.e. gender, marital status, # of TV’s in home.)
- there is no decimals in there values*
Define Continous Variables
Variables that take on any value ( e.g. speed, paw- lick latency, amt. of milk produced by cow etc.)
Variable could assume any value b/w lowest number and highest points on the scale.
Note: nominal variables can never be continuous b/c they are not ordered along any continum
Define Independant Variable
Those variables controlled by the experimenter.
i.e. forms of therapy, placement of stimulation electrodes, methods of treatment etc.
Define Dependant Variables
The variables being measured; data or score
(i.e. those that are not under the experimenters control- the data)
“D” for dependant Variable and “D” for Data
Define Random Assignment
The allocation or assignment of participants to groups by a random process.
Define Random Sampling
Each person of a population has an equal opportunity to be in the study.
(i.e. names drawn from a hat)
Define Constant
A number that does not change in value in a given situation
Define Frequency Distribution
A distribution in which the values of a dependant variable are tabled or plotted against their frequency of occurrence.
Define Real Lower Limit
The point halfway between the bottom of one interval and the top of one below it.
