SPSSSPSS

Basic stats Basic stats guideguide

Dr. Craig Jackson Dr. Craig Jackson Senior Lecturer in Health PsychologySenior Lecturer in Health Psychology

Faculty of HealthBirmingham City University

craig.jackson@bcu.ac.ukcraig.jackson@bcu.ac.uk

Types of Data / VariablesTypes of Data / Variables

ContinuousContinuous DiscreteDiscrete

BPBP ChildrenChildrenHeightHeight No. colds in last 12 monthsNo. colds in last 12 monthsWeightWeight Age last birthdayAge last birthdayAgeAgeBMIBMI

OrdinalOrdinal NominalNominal

Grade of “condition”Grade of “condition” SexSexPositions in race 1Positions in race 1stst 2 2ndnd 3 3rdrd Hair colourHair colour““BetterBetter - Same – Worse” - Same – Worse” Blood groupBlood groupHeight groupsHeight groups Eye colourEye colourAge groupsAge groups EthnicityEthnicity

Types of statistics / analysesTypes of statistics / analyses

DESCRIPTIVE STATISTICSDESCRIPTIVE STATISTICS Describing a phenomenaDescribing a phenomena

FrequenciesFrequencies How many…How many…Basic measurementsBasic measurements Meters, seconds, cmMeters, seconds, cm33, IQ, IQ

INFERENTIAL STATISTICSINFERENTIAL STATISTICS Inferences about phenomenaInferences about phenomena

Hypothesis TestingHypothesis Testing Proving or disproving theoriesProving or disproving theoriesConfidence IntervalsConfidence Intervals If sample relates to the larger populationIf sample relates to the larger populationCorrelationCorrelation Associations between phenomena Associations between phenomena Significance testingSignificance testing e.g diet and healthe.g diet and health

25 cells25 cells

22 cells22 cells

24 cells24 cells

21 cells21 cells

Total Total = 92 cells= 92 cellsMean Mean = 23 cells= 23 cellsSDSD = 1.8 cells= 1.8 cells

26

25

24

23

22

21

20

Multiple MeasurementMultiple Measurement

NN AgeAge IQIQ

11 2020 10010022 2020 10010033 2020 10010044 2020 10010055 2020 10010066 2020 10010077 2020 10010088 2020 10010099 2020 1001001010 2020 100100

TotalTotal 200200 10001000MeanMean 2020 100100SDSD 00 00

NN AgeAge IQIQ

11 1818 10010022 2020 11011033 2222 11911944 2424 10110155 2626 10510566 2121 11311377 1919 12012088 2525 11911999 2020 1141141010 2121 101101

TotalTotal 216216 11021102MeanMean 21.621.6 110.2110.2SDSD ± 4.2± 4.2 ± 19.2 ± 19.2

NN AgeAge IQIQ

11 1818 10010022 2020 11011033 2222 11911944 2424 10110155 2626 10510566 2121 11311377 1919 12012088 2525 11911999 2020 1141141010 4545 156156

TotalTotal 240240 11571157MeanMean 2424 115.7115.7SDSD ± 8.5± 8.5 ± 30.2 ± 30.2

Small samples spoil researchSmall samples spoil research

DispersionDispersion

RangeRange Spread of dataSpread of data

MeanMean Arithmetic averageArithmetic average

MedianMedian LocationLocation

ModeMode FrequencyFrequency

SDSD Spread of dataSpread of dataabout the meanabout the mean

RangeRange 50-112 mmHg50-112 mmHgMeanMean 82mmHg82mmHg MedianMedian 82mmHg82mmHg ModeMode 82mmHg82mmHgSDSD ± 10mmHg± 10mmHg

Central Tendency and AveragesCentral Tendency and Averages

ModeMode MedianMedian MeanMean

Patient comfort ratingPatient comfort rating

1010 99 88 77 66 55 44 33 22 11

3131 2727 7070 121121 140140 129129 128128 9090 8080 6262FrequencyFrequency