Psych 258 Ch 2

Front 1

Frequency Distribution

Back 1

organized tabulation of the number individuals located in each category on the SOM

- ranks and groups

Front 2

Two Elements of a Frequency Distribution

Back 2

1. a set of categories that make up the original scale of measurement

2. a record of the number of individuals in each category (frequency)

Front 3

Frequency Distribution Tables

Back 3

- simplest presentation style

- listing X(score) value categories (highest to lowest?) and recording frequency in adjacent column

- x for scores
- f for frequencies

Front 4

X column in FDT represents?

Back 4

- SOM

Front 5

sigma f =

Back 5

N

Front 6

first step in sigma X +2...

Back 6

isolate x scores

ex 5 6 8 8

N= sigma f = 4

sigma x+2 =

(5+2) + (6+2) + (8+2) + (8+2)

sigma f/N= gives you the number of values

if sigma f= 4 then 4 scores need to isolated and any further process acted upon them before summation

Front 7

explaining f...

Back 7

- how many times a particular score event was reported (observed and measured)

- sigma f establishes the number of values reported by the FDT

Front 8

x ... f... and f(x)...

Back 8

- x = score category(value category)

- f = number of times a specific score category was reported

- f(x) - raw value of represented by score category and frequency in FDT

Front 9

What are relative frequencies?

Back 9

- proportion of frequency compared to total frequency

- p = f/N

Front 10

percentage

Back 10

- 100(f/n)

Front 11

How does group frequencies relate to the purpose of FDT?

Back 11

- relatively organized simple picture of data

- rather listing individual values grouping intervals can help for a concise presentation of data

Front 12

Group Frequencies

Back 12

- groups of scores vs individual values

- this change effects x column labeling

Front 13

What are Group Frequencies also called...

Back 13

class intervals

Front 14

Guidelines (ruleS) for FDT and class intervals

Back 14

1. approx 10 intervals

2. Simple Width (easily multiple sizes)

3. Bottom Score multiple of width scale

4. Interval Width Consistence (no gaps or overlaps // 1 score 1 interval)

Range --> highest - lowest + 1

Front 15

Establishing Scalar Value

Back 15

range = highest - lowest +1

divided by 10 rounded to the nearest easily divisible number

Front 16

Histogram

Back 16

- numerical scores (as categories) on x axis

- bar above the x value

a. height - corresponding to the frequency or that category

b. width - extends to real limits of the category

Front 17

Polygons

Back 17

- ratio/interval
- numeric scores

steps

- dot centered above each category (height = frequency)

- a continuous line connects dots

- line extends below lowest score and above highest score

Front 18

Steps for making Frequency Distribution Table:

Back 18

make list of each possible value from high to low
 record frequency of each value on list
figure percentage (or proportion) of scores for each value

Front 19

Grouped Frequency

Back 19

- grouping values

- usng many possible values

Front 20

Histogram

Back 20

- a bar chart

- for numerical scores

- bars touch

Front 21

two types of frquency distruibution graphs for numeric ratio and interval

Back 21

- polygons and historgrams

Front 22

Bar graph is for

Back 22

- nominal and ordinal scales

Front 23

Steps for creating a histogram:

Back 23

Make frequency table
List numerical scores along bottom from lowest to highest
Make scale of frequencies along left edge starting from zero at bottom
Make bar above each value with height for frequency of that value

Front 24

Frequency Distribution Graph: Polygon

Back 24

Line graph
Line moves from point to point
Height of each point shows number of scores with that value

Front 25

relative frequency and smooth curves

Back 25

- large poulation ways of representing unaccounted data

- relative frequency of scores is a comparision of categories and smooth curve shows relative changes in scores with smooth line that dont cross over "real dots"

Front 26

Three Characteristics that completely decribe any distribution:

Back 26

- shape, central tendency, variability

Front 27

variability

Back 27

- whether scores are clustered or spread out

Front 28

symmetrical distribution

Back 28

line down the middle creates two mirror images

Front 29

skewed distribution

Back 29

- distribution stacked on one side

Front 30

tail

Back 30

the direction in which the distribution tapers off

Front 31

whether a skewed graph is positive or negative dpends on ...

Back 31

- the direction of the tail...

- tail on lower limit side it is negatively skewed

- tail on upper limit positively skewed