Descriptive Stats Final.pptx

Question 1

the reserch process

Answer 1

formulate hypothasis > design study> conduct study>collect data

Question 2

how to summarize data?

Answer 2

statatistics:
1-descriptive statistic
2-inferential statistics

reserchers want to convey maximum information using minimum space

Question 3

what is the purpose of descriptive statistic?

Answer 3

-summarize mass of data points

understanding and interpreteting
visual display

-

Question 4

scales of measures

Answer 4

1-Nominal
2-ordinal
3-interval
4-ratio

Question 5

nominals

Answer 5

-a group or categorization
-no order or direction
-summarize by proportions,percentage or the mode

Question 6

ordinal

Answer 6

ranked order
ex:first,second,third

Question 7

Interval

Answer 7

numerical scales in which intervals have the same interpretation throughout,but no true zero

Question 8

ratio

Answer 8

an interval scale with a true zero reference point

Question 9

measures of central data

Answer 9

-mean
-median
-mode

Question 10

mean

Answer 10

=arithmetic avarage
-uses information from every score

Add up all scores in each group and divide by the number of scores in each group.

Question 11

mediam
=score that diveds group in half

Answer 11

50% above or below
used when have extreme outliners

Put scores in order. Count number of scores.
 If odd #: identify the middlemost score.
 If even#: identify two middle scores, take average of them

Question 12

mode

Answer 12

=most frequent occuring score

Question 13

when do we use mode

Answer 13

Whenever it’s most descriptively
informative to report the most frequently
occurring score.

Question 14

when we use median

Answer 14

Whenever it’s most descriptively informative
to report the value for which equal numbers
of people score higher and lower

Question 15

mean downside

Answer 15

affected by outline

Question 16

mean upside

Answer 16

with incresing sample size,outlines has less efect on the mean

maximize use of all data

mathematical properties that enable us
to use it in statistical analysis

Question 17

outliers

Answer 17

extreme scores

Question 18

varablity

Answer 18

a spread in a distribution of scores

amound spread measured by standerad deviation

Question 19

measure of variability

Answer 19

range(max-min)
variance
standerd deviation

Question 20

standerd deviation

Answer 20

A measure of variability that enables
reference to the Normal Distribution so
it’s meaningful (as opposed to variance)

Defines what’s “normal” for that variable
Descriptive Statistics

Question 21

normal distribution

Answer 21

50%
50%

Answer 22

-1 sd(below mean)
mean
1sd(above mean

Question 23

types of descriptive statistics

Answer 23

meausre of central tendacies(mean,median,mode)

measures of variability (range,varience,standered deviation)

measure of relationship
(correlation r and r square
multiple regression
multiple corelation

Question 24

Rough standards for interpreting size
of effect in social sciences:

Answer 24

r=

0.1 to 0.2 small
0.3 medium
0.4 and up large

Question 25

r squared means

Answer 25

a proportion

r squared= 0.28 means that 28% of the
variance in MC scores is predicted by
written scores & vice versa

take r and multiply 2

Question 26

varience in score

Answer 26

r squered=0 no overlap
r squared = 1 complete overlap