Research Lecture 4

Question 1

DGI is a ___ measure

Answer 1

ordinal

note: uses a 4 point ordinal scale (0-3) to score each item

Question 2

The DGI is use to rank an individuals performance in dynamic gait tasks rather than precisely measure amt of change or improvement

Question 3

methods for organizing and summarizing data

Answer 3

descriptive statistics

for ex: tables and graphs used to organize data and descriptive values (avg scores) are used to summarize data

Question 4

descriptive value for a population is ___

Answer 4

parameter

Question 5

descriptive value for a sample is ____

Answer 5

statistic

Question 6

number of cases:
population
sample statistic

Answer 6

population: N
sample statistic: n

Question 7

mean
population
sample statistic

Answer 7

Question 8

proportion
population
sample statistic

Answer 8

Question 9

variance

Answer 9

Question 10

standard deviation

Answer 10

Question 11

correlation

Answer 11

Question 12

regression coefficient

Answer 12

Question 13

descriptive statistics

after collecting data the first task for a researcher is to _____ and ____ the data to get an general overview of the results

Answer 13

organize and simplify

Question 14

one method of simplifying and organizing data is to ____

Answer 14

construct a frequency distribution

Question 15

presents an organized picture of the entire set of scores, and it shows where each individual is located relative to others in the distribution

Answer 15

frequency distribution

Question 16

used when a set of scores covers a wide range of values

Answer 16

grouped frequency distribution

Question 17

frequency distribitions are displated as

Answer 17

histograms

Question 18

if the scores in population are measured on an interval or ratio scale and the N is large, it’s customary to present the distribution as a ____

Answer 18

smooth curve rather than a jagged histogram

Question 19

the smooth curve emphaizes

Answer 19

the fact that the distribitoin is not showing the exact freq in each category

Question 20

examples of smooth curves

Answer 20

IQ
GRE
SAT

Question 21

ideally you want the shape of your data distribution to be _____

Answer 21

symmetrical or have a normal distribution

Question 22

skewed

Answer 22

scores pile up on one side of distribution leaving a tail of a few extreme values on the other side

Question 23

two sides are close to mirror images of each other

Answer 23

symmetrical

Question 24

non symmetrical distribition of data

Answer 24

skewed

Question 25

scores bunched at low values with the tail pointing to the high values

Answer 25

postive skew

Question 26

scored bunched at high values with tail pointing to low values

Answer 26

negative skew

Question 27

kurtosis

Answer 27

the peakedness of the distribution leptokurtic vs platykurtic

Question 28

leptokurtic

Answer 28

higher and thinner peak

Question 29

platykurtic

Answer 29

lower and broader peak

Question 30

used to determine whether sample data has been drawn from a normally distributed population

Answer 30

normality test

Question 31

generally performed to verify whether the data involved in research have a normal distribution

Answer 31

normality test

Question 32

if it is found that sample data was not drawn from the normally distributed population ____

Answer 32

there are statistical steps that should be taken

Question 33

stem and leaf display

Answer 33

another way to display frequency distribution -each score is divided into a stem consisting of the first digit or digits and a leaf consisting of the final digits -then go through the list of scores, one at a time, and write the leaf for each score beside its stem

Question 34

a stat measure that describes the center of the distribution and represents the entire distribution of scores as a single number

Answer 34

central tendency

Question 35

three commonly used technique for measuring central tendency

Answer 35

mode mean median

Question 36

mode

Answer 36

the frequent score

Question 37

bimodal vs multimodal

Answer 37

having two modes having several modes

Question 38

what data is mode appropriate for

Answer 38

nominal ordinal interval ratio

Question 39

median

Answer 39

if the scores in a distribution are listed in order from smallest to largest, midpoint of list

Question 40

50% of scores in the distribution have values that are equal to or less than the median

Answer 40

true

Question 41

median is appropriate for what levels of data

Answer 41

ordinal interval ratio

Question 42

median is not appropriate for

Answer 42

nominal data

Question 43

advatange of the median

Answer 43

unaffected by extreme scores

Question 44

the most commonly used central tendency

Answer 44

mean

Question 45

computation of the mean requires scores that are numerical values measured on _____

Answer 45

interval/ratio scale

Question 46

DO NOT DO INTERVAL/RATIO STATS ON ORDINAL OR NOMINAL DATA

Question 47

Is mean affected by extreme scores

Answer 47

yes

Question 48

can you do mean for GDI

Answer 48

no because its ordinal

Question 49

should you report the mean? when a distribution contains a few extreme scores (skewed), the mean will be pulled toward the extreme (towards the tail). in this case, the mean will not provide a "central" value

Answer 49

no

Question 50

should you report the mean? with data from nominal scale it is impossible to compute a mean, and when data are measured on an ordinal scale(ranks)

Answer 50

no

Question 51

should you report the mean? mean of gender (coded as 0 and 1)

Answer 51

no

Question 52

in a symmetrical distribution, the ___ and __ are always equal

Answer 52

mean and median

Question 53

in a skewed distribution the mode will be located at the peak at _____ the mean will be displaced towards the ____ on the other side the median is usually located?

Answer 53

the peak on one side tail on the other side between mean and mode

Question 54

measure to express how spread out the scores are in a distribution

Answer 54

variability

Question 55

what accompanies a measure of central tendency

Answer 55

variability

Question 56

variability serves as both a ___ measure and an important component of most ____

Answer 56

descriptive measure inferiential stat

Question 57

as a _______ variability measures the degree to which the scores are spread out or clustered together in a distribution

Answer 57

descriptive statistics

Question 58

variability provides a measure of how accurately any individual score or sample represents the entire population

Answer 58

inferential statistics

Question 59

less variability -->

Answer 59

better representation