Playing with SPSS: Before Your data collection Francis Duah Maths Skills Centre, Academic Support Office francis.duah@york.ac.uk

Session Outline Quantitative Data Analysis : What training is available and where? Advice on independent learning and self-tutoring Sources of authentic research data SPSS demonstration and practical exercises

Quantitative Data Analysis Face to face training PG Statistics workshops at York http://www.quantitativemethods.ac.uk/ http://aqmen.ac.uk/ http://www.ncrm.ac.uk/training/

Quantitative Data Analysis Self-tutoring and Independent Learning https://www.discoveringstatistics.com/ http://libguides.library.kent.edu/SPSS/ExploringData http://calcnet.mth.cmich.edu/org/spss/Prjs_DataSets.htm https://www.youtube.co.uk

Advice: Play with authentic data Before you collect your data, “Practise and Practise” using SPSS Real Datasets Methodological approach Design your questionnaire bearing in mind the following: Ask questions you intend to analyse Consider how you might analyse the questionnaire

Sources of authentic datasets Other UK Data Service Census At School - International Project http://www.censusatschool.com/rds.html http://ww2.amstat.org/censusatschool/index.cfm http://www.cas.abs.gov.au/cgi-local/cassampler.pl

Sources of authentic datasets Other http://library.ncu.edu/dw/index/313 http://calcnet.mth.cmich.edu/org/spss/Prjs_DataSets.htm

What should your statistical practice entail? Descriptive Statistical Analysis Explore nominal and/or ordinal variables using Bar/Pie charts Explore your data to obtain descriptive statistics of your variables Explore the distribution of your continuous/interval scale variables Using charts Statistical tests

What should your statistical practice entail? Inferential Statistical Analysis Look for association between nominal variables and/or ordinal variables Look for differences in mean averages for groups (Between subjects) in with respect to some continuous variables Look for differences between the mean average for repeated measurements of continuous variables (Within subjects)

What should your statistical practice entail? Model development Look for bivariate relationships between continuous/scale variables Using Pearson correlation or Spearman correlation Develop linear models that fit your data Simple or multiple regression analysis Linear mixed models

Excel Files to Copy Filenames armspan.xlsx heights.xlsx gpapoints.xlsx exam.xlsx

Research Article Reeves SL, Varakamin C, Henry CJ. The relationship between arm-span measurement and height with special reference to gender and ethnicity Eur J Clin Nutr. 1996 Jun; 50(6):398-400.

Abstract OBJECTIVE: The relationship between height and arm-span measurement in both sexes and different ethnic groups was studied in order to assess the use of the arm-span measurement as a suitable proxy indicator for height. SETTING: School of Biological and Molecular Sciences, Oxford Brookes University. SUBJECTS: Five hundred and fifty-three subjects (272 male and 281 female) aged 23.3 years (s.d. 5.5). RESULTS: Correlation coefficients (r = 0.73-0.89) indicated a clear association between arm-span measurements and height in all groups. However, arm-span was found to be significantly different (P < 0.01) from height in two ethnic groups, the Afro-Caribbean's of both sexes and Asian males. This suggests that arm-span measurements may be an inappropriate proxy for height in certain populations. CONCLUSION: The arm-span measurement and height relationship is significantly different in Afro-Caribbean and Asian males. This suggests that any future studies attempting to use arm-span measurement as a proxy for height must consider these ethnic differences.

Practical – Demonstration 1 Goal: To develop a model for predicting the height of a person Open the Excel file armspan.xlsx Obtain Descriptive Statistics of the first seven variables Differences Is there a difference between males and females heights? Is there a difference between males and females arm span? Look for bivariate relationships between continuous/scale variables Develop linear regression models for prediction of height. Which independent variables significantly predict height?

Goal To develop a model for predicting the height of a person Practical – Exercise 1 Goal To develop a model for predicting the height of a person Open the Excel file heights.xlsx Obtain Descriptive Statistics of the first seven variables. Differences Is there a difference between males and females heights? Is there a difference between males and females belly buttons height? Look for bivariate relationships between continuous/scale variables Develop linear regression models for prediction of height Which independent variables significantly predict height?

Practical – Demonstration 2 Goal To develop a model for predicting the MBA GPA Scores Open the Excel file gpapoints.xlsx Obtain Descriptive Statistics of the variables In relation to height, arm span, and belly button Is there a difference between males and females mbagpa? Is there a difference between males and females gmatscore? Is there a difference between males and females belly degreegpa? Look for bivariate relationships between continuous/scale variables Develop linear regression models for prediction of mbagpa. Which independent variables significantly predict mbagpa?

Practical – Demonstration 2 Goal To develop a model for predicting the EXAM MARKS of a person Open the Excel file exam.xlsx Obtain Descriptive Statistics of the variables. Differences Is there a difference between males and females A-level scores? Is there a difference between males and females exam results? Is there a difference between males and females anxiety score? Is there difference between males and females number of hours of revision? Look for bivariate relationships between continuous/scale variables Develop regression models that may be used to predict exam marks Which independent variables significantly predict exam marks?

Take Home Message Practice and practice with authentic research data. Seek advice from your supervisor. Consult the Maths Skills Centre at the earliest opportunity. Attend PG Statistics Workshops without fail.

Thank You for Listening Keep in touch Francis Duah Maths Skills Centre, Academic Support Office francis.duah@york.ac.uk