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Basics of SPSS: Part 2

ASK Week – Autumn 2012


Choose appropriate graphical summaries

Charts and graphs in SPSS

Choose appropriate numerical summaries

Descriptive statistics in SPSS

Frequency tables in SPSS


 Located

on Blackboard in the following:

Go to the Organisation Academic Skills.  Workshop slides  ASK Week Autumn 2012  Basics of SPSS: Part 1 and Part 2  Download and save the SPSS data file: 

EmployeeSurvey.sav


Part 1:

Representing Data Graphically


All variables listed here

Build your chart here

Select chart type

Select chart format


One

Nominal or Ordinal Variable

Bar Chart

Pie Chart


What is your ethnicity? (please tick one)

White/European Asian West Indian African Other

Produce a bar chart and a pie chart for Ethnicity.


Bar Charts Simple Bar Chart


Pie Chart Pie Chart


Two

Nominal or Ordinal Variables

Clustered Bar Chart


Two

Nominal or Ordinal Variables

Stacked Bar Chart


“I am very committed to this organisation.� Strongly Disagree 1

Disagree

2

Gender

Neutral

Agree

3

4

Male

Strongly Agree 5

Female

(please tick one)

Produce a clustered bar chart or a stacked bar chart to summarise commitment by gender.


Bar Charts Clustered Bar Chart

Stacked Bar Chart


One

Scale Variable

Histogram

Boxplot


What is your gross annual income?

Produce a histogram and a boxplot to summarise gross annual income.


Histograms Simple Histogram


Boxplots 1D Boxplot


Two

Scale Variables

Scatterplot


Scatterplots Simple Scatterplot


What is your gross annual income? Age last birthday (in years)?

Produce a scatterplot to show the relationship between income and age.


Two or more

Related Scale

Variables

‘Related’ refers to ‘Repeated Measures’

Bar Chart of Means

Line Chart of Means


Produce a bar/line chart of means to summarise employees total competency score at each of the 3 time periods.


Bar Charts Simple Bar Chart


Line Charts Simple Line Chart


One Scale & One

Categorical

Bar Chart of Means

Variable

Line Chart of Means


Rated Skill of work: Unskilled

Semi-Skilled

Fairly Skilled

Highly Skilled

1

2

3

4

What is your gross annual income? Produce a bar/line chart of means to summarise income by rated skill.


Bar Charts Simple Bar Chart


Line Charts Simple Line Chart


Right Click Edit Content In Separate Window


Reduce chart size and Apply changes


Right Click to view more options

E.g., Transpose Chart


 There’s

much more in Chart Editor  You can change:  Colours  Fonts  Axis

labels  Data labels  Insert trend lines  Rearrange (or remove) variables  …the list goes on


 For

more detailed examples go to:

 Academic

Skills on Blackboard  Statistics and SPSS  Statistics using SPSS: Resources  Charts and Graphs  Find the slides entitled: “SPSS Chart Builder”


Part 2:

Representing Data Numerically


(All Descriptive Stats)

(Limited Descriptive Stats)

(Limited Descriptive Stats)

Mean, Median, Mode

Median = The middle value in an ordered data set. It splits the data into 2 equal parts. Mode = Most frequent value.


(All Descriptive Stats)

(Limited Descriptive Stats)

(Limited Descriptive Stats)

Mean, Median, Mode Stdev, Variance Range, IQR Min, Max

Standard Deviation & Variance Measure how spread out the data is with respect to the mean

Range Spread of the data (Max – Min)


(All Descriptive Stats)

(Limited Descriptive Stats)

(Limited Descriptive Stats)

Mean, Median, Mode Stdev, Variance Range, IQR Min, Max Skewness, Kurtosis Skewness & Kurtosis Measure how close a histogram is to a normal distribution.


(All Descriptive Stats)

(Limited Descriptive Stats)

(Limited Descriptive Stats)

Mean, Median, Mode Frequency Table Frequency Table Stdev, Variance Median, Mode Mode Range, IQR Min, Max Skewness, Kurtosis


ď‚ž Ordinal ď‚Ą

data

Mean and stdev OR frequencies and percentages? 1.87

4.69

Mean = 3.28 Stdev = 1.41

1

2

3

4

5

Strongly Disagree

Disagree

Neutral

Agree

Strongly Agree

12%

22.7%

21.3%

13.3%

30.7%


Summarise Responses What is your ethnicity? (please tick one)

White/European Asian West Indian African Other

What is the variable? Level of Measurement? Appropriate numerical summary?


Statistics Frequency tables Charts • Bar • Pie • Histogram


Representing data Numerically Nominal Variable e.g., Ethnicity


Representing data Numerically Nominal Variable e.g., Ethnicity


Summarise Responses “I am very committed to this organisation.� Strongly Disagree 1

Disagree 2

Neutral

Agree

3

4

What is the variable? Level of Measurement? Appropriate numerical summary?

Strongly Agree 5


Representing data Numerically Ordinal Variable e.g., Organisational Commitment


Representing data Numerically Ordinal Variable e.g., Organisational Commitment


Representing data Numerically Out of the total sample size (e.g., 70)

14 out of 70 is 20.0%


Representing data Numerically Out of the total sample size (e.g., 70)

16 out of 70 is 22.9%


Representing data Numerically Out of the total sample size (e.g., 70)

68 out of 70 is 97.1%


Representing data Numerically Out of the total responses (i.e., 68)

14 out of 68 is 20.6%


Representing data Numerically Out of the total responses (i.e., 68)

16 out of 68 is 23.5%


Representing data Numerically

Adds the Valid Percentages Same as first valid percent


Representing data Numerically

Adds the Valid Percentages Adds the 1st two valid percents


Representing data Numerically

Adds the Valid Percentages Adds the 1st three valid percents


Summarise Responses What is your gross annual income?

What is the variable? Level of Measurement? Appropriate numerical summary?


Representing data Numerically Scale Variable e.g., Gross Annual Income

Select any of these Descriptives


Representing data Numerically

The average income: ÂŁ7819.12


Representing data Numerically

The middle income: ÂŁ7800 Half earned less Half earned more


Representing data Numerically

One of the most frequent incomes: ÂŁ6800


Representing data Numerically

On average, each employee’s income is approximately £998 different from the mean


Representing data Numerically

The lowest income of all employees: ÂŁ5900


Representing data Numerically

The highest income of all employees: ÂŁ10,500


Cross Tabulation Table use ‘Crosstabs’ in SPSS

All Descriptive Statistics ‘Split file’ then use ‘Frequencies’ in SPSS


Summarise Responses “I am very committed to this organisation.� Strongly Disagree 1

Disagree 2

Gender

Neutral

Agree

3

4

Male

Female

(please tick one)

What are the variables?

Level of Measurement? Appropriate numerical summary?

Strongly Agree 5


Crosstabs table (Counts or %’s) • Observed tallies • Expected tallies

Crosstab statistics • Chi-square • Correlations

Clustered bar charts


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

Observed count frequency observed in the sample


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

Column % % of participants using column totals


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

Row % % of participants using row totals


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

Total % % of participants using sample size


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

6 Females Strongly Disagreed


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

8 Males Agreed


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

19 participants were Undecided


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

6 of 38 Females Strongly Disagreed 15.8% of females


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

8 of 30 Males Agreed 26.7% of males


Representing data Numerically Two Categorical Variables e.g., Gender by Commitment

19 of 68 Participants were Undecided 27.9% of the sample


Summarise Responses What is your gross annual income? Gender

Male

Female

(please tick one)

What are the variables?

Level of Measurement? Appropriate numerical summary?


Two methods: 1. ‘Explore’ option 2. Split file, then ‘Frequencies’ option We will use the 2nd method.


Method 2


Split the file by Gender Output for males and females will be in one table

Separate output tables for males and females File must be sorted!

Categorical Variable

Method 2


Split the file by Gender

The file is sorted All females are listed first, then all males

Method 2


Statistics Frequency tables Charts • Bar • Pie • Histogram

Now get stats for Annual Income • Use ‘Frequencies’ • Output will be split by Gender Method 2


Representing data Numerically Scale Variable e.g., Gross Annual Income

Select any of these Descriptives

Method 2


Representing data Numerically

Split File Option to Compare Groups Output for males and females is in one table

Method 2


Recall the Split File output options Output for males and females will be in one table

Separate output tables for males and females

Method 2


Representing data Numerically

Split File Option to Organise Output by Groups Separate output table for males and females

Method 2


Remember to go back and ‘Analyse all cases, do not create groups’

Method 2


SPSS Survival Manual, 4th Edition (2010) by Julie Pallant. (For SPSS Version 15 or later)

Discovering Statistics Using SPSS, 3rd Edition (2009) by Andy Field. (For SPSS Version 15 or later)


ASK Week – Autumn 2012

+

Find the slides (and much more) on Blackboard


Basics of SPSS, Part 2