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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
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Find the slides (and much more) on Blackboard