Psychology 202 - Test 1 Flashcards Preview

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Flashcards in Psychology 202 - Test 1 Deck (36):
1

data

information

2

statistics

branch of mathematics focused on organization, analysis, and interpretation of a group of numbers

3

descriptive statistics

used to describe a group of numbers from a study

4

inferential

used to draw conclusions from collected data

5

variable

characteristic of something or someone that can have different vaules
i.e. people, [usually] mind

6

constant

if the characteristic does not/can not vary
- dependent on perspective

7

values

numbr or category

8

score

particular value on a variable
- tells how much there is of what is being measured

9

equal-interval variable

a variable in which the numbers stand for approximately equal amounts of what is being measured
i.e. in stress rating, difference between 4 & 6 is the same as the difference between 7 & 9

10

ratio scale

used if the equal-interval variable has an absolute zero point
i.e. number of siblings > zero means something and is important

11

absolute zero point

value of zero on the variable indicates complete absence of the variable
i.e. number of siblings > zero = no siblings

12

rank order variable

a variable where numbers stand ONLY for the relative ranking
- ordinal variables
- provides less info/less accurate than equal-interval but sometimes easier/only info available
i.e. olympics (1,2,3) but 1 & 2 can be close while three was far behind them

13

nominal variable

variable in which the values differ as names or categories
i.e. favorite sports team
*can go from nominal to numeric but not the other way around

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discrete variable

specific values and nothing in between

15

continuous variable

has infinite number of values in between any two values

16

population

the entire group of people that is studied
- can range from small to the entire world depending on the question

17

sample

a subset of the population
- small/more manageable group to study
-(hopefully) identical to population > generalizability

18

frequency table

table that lists all values that are possible along with the number of cases that have that value

19

relative frequency table

tells frequency AND frequency relative to other scores
- divide number of cases in each value by total number of cases

20

histogram

graphic representatio of frequency of scores
- x = possible values
- y = number of cases

21

number of peaks (histogram)

1 peak = unimodal
2 peaks = bimodal
3+ peaks = multimodal

22

symmetrical distributions

roughly equal scores on both sides of the peak

23

skewed distributions

unequal scores on each side of the peak
- positively skewed > more scores on left side
- negatively skewed > more scores on the right side

24

normal curve

symmetrical, bell shaped curve that has changes in curve direction at exactly 1 standard deviation above and 1 standard deviation below the mean
- theoretical distribution
- mode, median, and mean are all exactly the same number
- Middle point = average point = most frequent point
- more scores you have = closer you get to normal distribution
- assume data would look like normal curve if we had enough
- 68.2% = 1 SD
- 95.4% = 2 SD
- 99.7% = 3 SD

25

platykurtic

most values have roughly the same frequency
- upside down plate

26

leptokurtic

very few values have a high frequency
- tower

27

measure of central tendency

single number that we use to describe a distribution of scores
- representative of all scores

28

mean

mathematical average of a group of scores
- μ = population, M = sample
- mean = Σx/N
- most stable measure of central tendency
- takes all scores into account
- can be value no one got
- incredibly sensative to outliers

29

mode

most frequent score in a distribution
- only measure that can be used with nominal data
- says nothing about other scores
-doesn't tell the placement of the score

30

median

score in the middle of a distribution
- scores in order from smallest to largest and find middle score
- can be the same as mode
- can be score no one has/received
- does not mean there is equality in the range

31

variability

the amount of variation in a distribution of scores

32

range

the difference between the highest and lowest score
- very unstable
- no additional stats calculated

33

variance

measure of variability that considers how different each score in a distribution is from the mean
- extremely important in stats
- population = δ
- sample = SD
- variance = Σ(x - M)²/N
- SS = Σ(x - μ)²

34

standard deviation

the average amount that a set of scores differ from one another (how much scores vary)
- population =
- sample = SD
- standard deviation = √Σ(x - μ)²/N

35

z-score

number of standard deviations above or below the mean an actual score is
- standardizes scores
- z = (x - M)/SD

36

z-scores > percent to value

- go to closest percent
- find percent and look at corresponding z-score
- invert z-score equation