william lodrigues module 2 describing your data 1...

William Lodrigues

Module 2 Describing Your Data

1 Running head: WILLIAM LODRIGUES

Describing Your Data

William Lodrigues, MS

Texas Woman’s University

William Lodrigues


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Select and use the appropriate statistical tests to describe the sample (e.g.: sex, age, marital status, education). State what statistics you used for each variable and provide rationale for your choice of statistics. Present and interpret your findings. Copy and paste relevant output from your SPSS run into your word file and provide a narrative summary of the output.

Statistics

sex

N Valid 271

Missing 0

Mode 0

sex

Frequency Percent Valid Percent

Cumulative

Percent

Valid female 150 55.4 55.4 55.4

male 121 44.6 44.6 100.0

Total 271 100.0 100.0

Due to sex being a nominal data in this chart, the descriptive statistic used was mode. In the table shown above, there are 271 valid respondents. There were no missing data. Of the 271 respondents, 55.4% were female and 44.6% were male. The most common variable (mode) was 0 for female.

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AGE Case Processing Summary

William Lodrigues


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Cases

Valid Missing Total

N Percent N Percent N Percent

age 248 91.5% 23 8.5% 271 100.0%

Descriptives

Statistic Std. Error

age Mean 43.87 .805

95% Confidence Interval for

Mean

Lower Bound 42.28

Upper Bound 45.46

5% Trimmed Mean 43.75

Median 44.00

Variance 160.882

Std. Deviation 12.684

Minimum 18

Maximum 84

Range 66

Interquartile Range 20

Skewness .075 .155

Kurtosis -.566 .308

Tests of Normality

Kolmogorov-Smirnova Shapiro-Wilk

Statistic df Sig. Statistic df Sig.

age .052 248 .099 .986 248 .019

a. Lilliefors Significance Correction

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age Stem-and-Leaf Plot Frequency Stem & Leaf 4.00 1 . 8999 12.00 2 . 112223333444 23.00 2 . 55556666667777788899999 24.00 3 . 000001111222222333344444 27.00 3 . 555555555566666677778889999 38.00 4 . 00000011111111122222222333333334444444 35.00 4 . 55556666667777777777888888888899999 29.00 5 . 00000011112222222333334444444 32.00 5 . 55555666667777777888888899999999 11.00 6 . 00002222333 10.00 6 . 5666667899 2.00 7 . 01 .00 7 . 1.00 8 . 4

William Lodrigues


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Age is a ratio variable, continuous and has a true zero. The statistics calculated were standard deviation, variance, range, minimum, maximum, kutosis, and skewness. There were a total of 271 cases with 248 (91.5%) being valid and 23 (8.5%) missing. The mean age was 43.87 with a standard deviation of 12.684. The minimum age was 18 and maximum was 84. The range (high to low) was 66 with a skewness of 0.075, slightly positive, and a Kurtosis of -.566, relatively flat. Kolmogorov-Smirnova has a value of 0.099 (greater than 0.05) indicating normality. The 5% Trimmed Mean, 43.75, and the mean, 43.87, are close meaning that the outlying cases are likely not to be a problem.

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William Lodrigues


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Marital Status

Statistics

marital status

N Valid 271

Missing 0

Mean 1.94

Median 2.00

Mode 2

Range 3

Minimum 1

Maximum 4

marital status


Cumulative

Percent

Valid single 54 19.9 19.9 19.9

married/defacto 188 69.4 69.4 89.3

divorced 21 7.7 7.7 97.0

widowed 8 3.0 3.0 100.0

Total 271 100.0 100.0

William Lodrigues


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Marital status is nominal data, categorical and qualitative. There were 271 valid respondents. There was no missing data. The mode was married (2), with 188 (69.4%) answering married. The smallest frequency was widowed with only 8 (3%), followed by divorced 21(7.7%), and single 54 (19.9%). There is not much else you can describe from this data.

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William Lodrigues


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Educational Level

Statistics

highest education level achieved

N Valid 269

Missing 2

Mean 4.10

Median 4.00

Mode 5

Range 4

Minimum 1

Maximum 5

highest education level achieved


Cumulative

Percent

Valid primary school 3 1.1 1.1 1.1

secondary school 33 12.2 12.3 13.4

trade training/ post secondary

training

30 11.1 11.2 24.5

undergraduate degree 71 26.2 26.4 50.9

postgraduate degree 132 48.7 49.1 100.0

Total 269 99.3 100.0

Missing System 2 .7

Total 271 100.0

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The educational level is an ordinal level of data, categorical and ranking with a single 0. The statistics able to be tested are simple frequencies: median, mode, minimum, maximum, and range. There were 269 valid respondents and 2 missing data (0.7%). The results state the median as 4, mode 5, range 4, minimum 1, and maximum 5. This tells us that there is no incorrect data entry (numbers less than 1 or greater than 5). The mode was post graduate degree with 132 (48.7%).

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Select four variables that would best describe the sleep patterns of this sample. State the variables that you selected with rationale. State the statistics you used for each variable and provide rationale for your choice of statistics. Present and interpret your findings. Copy and paste relevant output from your SPSS run into your word file and provide a narrative summary of the output.

William Lodrigues


10 The four variables that I selected are trouble falling sleeping, trouble staying asleep, waking during the night, and light sleeper. These four variables best describe sleep patterns. This is considered nominal data (categorical and qualitative). There is no reason to ask for means, standard deviations, and ranges for nominal data. You should only look at mode, minimum and maximum to examine your data. The minimum and maximum will help to see invalid data in the data sets.

Statistics

trouble falling

asleep?

trouble staying

asleep

waking during

night light sleeper?

N Valid 269 266 271 266

Missing 2 5 0 5

Mode 2 2 1 2

Minimum 1 1 1 1

Maximum 2 2 2 2

Frequency Table

trouble falling asleep?


Cumulative

Percent

Valid yes 106 39.1 39.4 39.4

no 163 60.1 60.6 100.0

Total 269 99.3 100.0

Missing System 2 .7

Total 271 100.0

There were a total of 271 respondents, with 2 (0.7%) missing data. Of the 269 that gave

valid data, 106 (39.1%) said they had trouble falling asleep, and 163 (60.1%) said they

had no trouble falling asleep. The mode is 2 (no); most people (60%) have no trouble

falling asleep. The min and max were 1 and 2, telling me no wrong data entries such as a

number 4.

William Lodrigues


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trouble staying asleep


Cumulative

Percent

Valid yes 116 42.8 43.6 43.6

no 150 55.4 56.4 100.0

Total 266 98.2 100.0

Missing System 5 1.8

Total 271 100.0

There were 271 respondents with 5 (1.8%) missing data. Of the remaining 266

respondents, 116 (42.8%) answered yes, have trouble staying asleep and 150 (55.4%) had

no trouble staying asleep. The mode is 2 (no); most do not have trouble staying asleep.

The min and max were 1 and 2 telling me there were no wrong data entries such as a

number 4.

waking during night


Cumulative

Percent

Valid yes 216 79.7 79.7 79.7

no 55 20.3 20.3 100.0

Total 271 100.0 100.0

There were 271 respondents with no missing data. Of the 271 respondents, 216 (79.7) stated waking during the night and 55 (20.3%) stated no to waking during the night. The mode was 1 (yes); most wake during the night. The min and max were 1 and 2 telling me there were no wrong data entries such as a number 4.

William Lodrigues


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light sleeper?


Cumulative

Percent

Valid yes 117 43.2 44.0 44.0

no 149 55.0 56.0 100.0

Total 266 98.2 100.0

Missing System 5 1.8

Total 271 100.0

There were a total of 271 respondents with 5 (1.8%) missing data. Of the 266 (98.2%) that did have valid data, 117 (43.2%) said yes, they were light sleepers and 149 (55.0%) said that they were not light sleepers. The mode was 2 (no); most are not light sleepers. The min and max were 1 and 2 telling me there were no wrong data entries such as a number 4.

Assess the distribution of scores on the sleepiness and associated sensations scale (totSAS) for people who fell they do/don’t have a sleep problem (problem). Are the scores normally distributed? Copy and paste relevant output and graphs from your run to support your answer. Did you find any outliers on this scale? Copy and paste relevant output and graphs from your run to support your answer. Compare the two distributions. Describe their similarities and differences.

Statistics

problem with sleep?

N Valid 269

Missing 2

Mode 2

Minimum 1

Maximum 2

problem with sleep?


Cumulative

Percent

William Lodrigues


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Valid yes 117 43.2 43.5 43.5

no 152 56.1 56.5 100.0

Total 269 99.3 100.0

Missing System 2 .7

Total 271 100.0

Due to the answers of yes and no being a nominal data in this chart, the descriptive statistic used was mode. There were 269 (99.3%) valid answers and 2 (0.7%) missing data. Of the 269 valid answers, 117 (43.2%) answered yes and 152 (56.1%) answered no. The mode was 2 (no), most answered that they did not have problems with sleep.

Case Processing Summary

Cases

Valid Missing Total


sleepy & assoc sensations

scale

251 92.6% 20 7.4% 271 100.0%

William Lodrigues


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Descriptives

Statistic Std. Error


scale

Mean 26.04 .664


Mean

Lower Bound 24.74

Upper Bound 27.35


Median 27.00

Variance 110.666


Minimum 5

Maximum 50

Range 45


Skewness -.057 .154

Kurtosis -1.130 .306

A scale is ordinal data, categorical and ranking with a single “0”. The 5 % trimmed mean is 26.02 and the mean is 26.04. If there are any extreme scores, they have no effect on the mean since the 5% trimmed mean is so close to the mean. The standard deviation is 10.520. This means that 68.2 % will be within one standard deviation, 10.520, of the mean, 26.04, in a normal distribution pattern. The skewness is -.057, or negative skewness, means that there are a cluster of scores at the high end. The Kurtosis is -1.130, meaning that the curve is relatively flat.

Extreme Values

Case Number

Identification

Number Value


scale

Highest 1 171 240 50

2 170 234 47

3 186 89 45

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4 212 42 45

5 30 26 44a

Lowest 1 152 211 5

2 164 200 6

3 156 546 7

4 145 420 8

5 132 59 8b

a. Only a partial list of cases with the value 44 are shown in the table of upper extremes.

b. Only a partial list of cases with the value 8 are shown in the table of lower extremes.

Tests of Normality




scale

.096 251 .000 .962 251 .000

The tests of normality is .096. With the results more than 0.05, the results are non-significant, or normality.


William Lodrigues


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sleepy & assoc sensations scale Stem-and-Leaf Plot Frequency Stem & Leaf .00 0 . 9.00 0 . 567888888 39.00 1 . 000000011111112222222333333333444444444 33.00 1 . 555555566666667777777788888888999 31.00 2 . 0000000000111123333333334444444 29.00 2 . 55555555666677777888888899999 41.00 3 . 00000000111111111122223333333344444444444 42.00 3 . 555555555555555566666666777777777888999999 23.00 4 . 00000000000001123344444 3.00 4 . 557 1.00 5 . 0 Stem width: 10 Each leaf: 1 case(s)

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Case Processing Summary

problem

with

sleep?

Cases

Valid Missing Total



scale

yes 111 94.9% 6 5.1% 117 100.0%

no 138 90.8% 14 9.2% 152 100.0%

To describe the data above, problems with sleep, there were 111 (94.9%) of the

respondents that entered yes for problems with sleep provided data for totsas with 6

(5.1%) not responding. Of the 269 respondents, 138 (90.8) entered no for problem with

sleep, and 14 (9.2%) had missing data.

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Descriptives

problem with sleep? Statistic Std. Error


scale

yes Mean 32.21 .781


Mean

Lower Bound 30.66

Upper Bound 33.75


Median 34.00

Variance 67.638


Minimum 10

Maximum 50

Range 40


Skewness -.643 .229

Kurtosis .149 .455

no Mean 21.22 .817


Mean

Lower Bound 19.60

Upper Bound 22.83


Median 18.50

Variance 92.069


Minimum 5

Maximum 44

Range 39


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Skewness .493 .206

Kurtosis -.791 .410

Extreme Values

problem with sleep? Case Number

Identification

Number Value


scale

yes Highest 1 171 240 50

2 170 234 47

3 186 89 45

4 212 42 45

5 30 26 44a

Lowest 1 224 537 10

2 233 206 12

3 204 45 12

4 270 423 13

5 256 289 13

no Highest 1 126 509 44

2 55 55 43

3 63 247 42

4 97 52 40

5 121 241 40b

Lowest 1 152 211 5

2 164 200 6

3 156 546 7

4 145 420 8

5 132 59 8c


b. Only a partial list of cases with the value 40 are shown in the table of upper extremes.

William Lodrigues


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Extreme Values

problem with sleep? Case Number

Identification

Number Value


scale

yes Highest 1 171 240 50

2 170 234 47

3 186 89 45

4 212 42 45

5 30 26 44a

Lowest 1 224 537 10

2 233 206 12

3 204 45 12

4 270 423 13

5 256 289 13

no Highest 1 126 509 44

2 55 55 43

3 63 247 42

4 97 52 40

5 121 241 40b

Lowest 1 152 211 5

2 164 200 6

3 156 546 7

4 145 420 8

5 132 59 8c


b. Only a partial list of cases with the value 40 are shown in the table of upper extremes.

c. Only a partial list of cases with the value 8 are shown in the table of lower extremes.

Tests of Normality

William Lodrigues


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problem

with

sleep?




scale

yes .136 111 .000 .961 111 .002

no .131 138 .000 .948 138 .000


The sig. Value is .000, meaning that a violation of the assumption of normality may be

present (Pallant, p.62).

William Lodrigues


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William Lodrigues


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William Lodrigues


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In this boxplot, SPSS considers 206, 289, 45, and 537 as outliers.

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