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Masters Comprehensive Exam > Statistics > Flashcards

Flashcards in Statistics Deck (129)
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1

population

set of all individuals of interest in a study population = parameter

2

parameter

numerical value that describes a population can be a single measurement or set of measurements

3

sample

set of individuals selected from a population, representative of population in a study sample = statistic

4

statistics

numerical value that describes a sample can be a single measurement or set of measurements

5

descriptive statistic

statistical procedures that are used to summarize, organize, simplify data - make raw score meaningful e.g. mean, median, mode

6

inferential statistics

techniques that allow us to study samples then make generalizations about the population - infer sample -> population

7

sampling error

discrepancy/ amount of error that exists between a sample statistic and population parameter - important to consider in inferential statistics

8

construct

internal attributes/ characteristics that cannot be directly observed but are useful for describing and explaining behavior - hypothetical e.g happiness

9

operational definition

defines construct in terms of observable behaviors e.g. intelligence defines as performance on IQ test

10

nominal scale

categorical organization - can only measure qualitative difference e.g gender, country of origin, hair color

11

ordinal scale

categories organized in a certain sequence, differences are quantitative - amount between one person and next is not consistent e.g. class rank, rating scale

12

interval scale

ordered categories that are intervals of exactly same size with an arbitrary zero point - 0 does not mean the absence of the construct being measured e.g. celsius scale, temp

13

ratio scale

interval scale with absolute zero point - can describe differences between categories in terms of ratios (one thing is 3 times larger than another) e.g. weight, height, speed

14

discrete variables

separate, indivisible categories - whole numbers or specific categories - no decimals e.g 3 goals scores

15

continuous variables

infinite number of possible values that fall between any two observed values - divisible into infinite number of fractional parts e.g. height

16

real limits

boundaries of intervals for scores that are represented on a continuous number line - each score has two limits, half way between scores (upper real limit, lower real limit) e.g. if you have observed value of 8, actually represents range from 7.5 - 8.5 (kind of like rounding)

17

correlational method

two variables observed to see if there is a relationship between the two

18

experimental method

establishes cause and effect relationship between variables - must manipulate one variable, observe second - controlled research situation

19

non-experimental method

variable determines group (those that have depression) - don't manipulate

20

independent variable

manipulated variable - 2+ treatment conditions

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dependent variable

observed for changes to assess effect

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control

does not receive manipulated experimental treatment, baseline for comparison

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quasi-independent variable

groups not created by manipulating independent variable - participent variable (male/female) - time variable (before/after)

24

summation notation

a way to represent scores n ∑ xi i = 1 i = the starting point of the scores n = the stopping point

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µ

population mean

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x

sample mean

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σ

population standard deviation

28

s

sample standard deviation

29

σ2

population variance

30

s2

sample variance

SS/n (df w/ sample)