Stage 4: Description, Analysis and

Interpretation

Primary Data Environmental Quality Assessment

Describe and justify how you used measurements of Central Tendency (averages) to analyse your data.

Using Excel measurements of mean and median Environmental Quality Scores were calculated (see next slide)

These measurement provide a typical Environmental Quality Score value for each location and can be used as an initial comparison point

Outer Suburbs - Quinton   Inner Suburbs - Ladywood

   

Measurement Value Measurement Value  

Mean 9 Mean -18  

Median 7       Median -18    

What did the results of these measurements show?

The average Environmental Quality Scores for Quinton are positive, between 7 (median) and 9 (mean) indicating that perceptions of this area are above average, whilst the average score for Ladywood is negative, -18 (both mean and median) indicating that this area is perceived to have an environmental quality  much lower than average.

Describe and Justify the use of Inter-Quartile Range  (IQR) data

Qunton LQ 4

Ladywoood UQ -12

 By comparing the level of overlap between the Inter-Quartile Range (IQR) for the  Quinton and Ladywood data it is possible to determine if a significant difference exists. (see next slide)

• As the upper quartile for Ladywood’s Environmental Quality Score is below the lower quartile for Quinton, it can be said that a significant difference exists between the perceived environmental quality of the two areas. Quinton has a significantly higher environmental quality than Ladywood

What did the overlap of the IQR for different data sets show?

Describe and Justify the use of the Mann Whitney U Test.

A Mann Whitney U Test will determine to a level of confidence (95%,99% or 99.9%) whether there is a significant difference between the Environmental Quality Scores for Quinton and Ladywood.

What did the results of this show?

• Using Minitab the results for this test are displayed below: Mann-Whitney Test and CI: Quinton EQA, Ladywood EQA

N MedianQuinton EQA 48 7.000Ladywood EQA 48 -17.500

Point estimate for ETA1-ETA2 is 26.00095.0 Percent CI for ETA1-ETA2 is (23.000,30.000)W = 3475.5Test of ETA1 = ETA2 vs ETA1 > ETA2 is significant at 0.0000The test is significant at 0.0000 This is the ‘p’ value.

See next slide for interpretation of ‘p’ values

p value Interpretation

>0.05 The result of the test is not significant

<0.05 With greater than 95% confidence the result is significant

<0.01 With greater than 99% confidence the result is significant

<0.001 With greater than 99.9% confidence the result is significant

• Therefore it can be said that with greater than 99.9% confidence, the Environmental Quality Scores for Quinton are significantly higher than those for Ladywood.

Census DataSummarise what the bar charts showed in terms of socio-economic indicators?

• For all of the indicators of wealth - Owner Occupied - 2 or more cars - Employed - Mngmnt/ Prof occupationsQuinton has a higher % than Ladywood and in most cases the average for Birmingham

• For all of the indicators of deprivation - Social rented - 0 cars - Unemployed - No QualificationsLadywood has a higher % than Quinton and in most cases the average for Birmingham

Police Crime DataDescribe and justify how you used measurements of Central Tendency ( averages) to analyse your data.

What did the results of these measurements show?

Describe and Justify the use of Inter-Quartile Range (IQR) data.

What did the overlap of the IQR for different data sets show?

Describe and Justify the use of the Mann Whitney U Test.

What did the results of this show?

YOU need to do this bit on your own!!

Use Minitab to complete the Mann Whitney U Test – see next slides for help

Great! I love doing statistics

Step 4.

Phew !Another section

complete