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How to analyze survey research data?
SPSS Interface Data Editor
• Variable view – Name – eg id, gen, schcat, a1, … (space bar, ?, ! *, !, …
considered as illegal characters) – Type – Width – Decimals – Label – ID, Gender, School Category, Item 1a, etc – Values – eg 1 – Strongly Disagree, 2 – Disagree, 3 – Neither
agree nor disagree, 4 – Agree, 5 – Strongly Agree – Missing – Columns – Align – Measure – Role
SPSS Interface Data Editor
• Data view
– Entering data
– Save file
Reliability Analysis
• Analyze > Scale > Reliability Analysis
• Overall
–Corrected Item –Total Correlation. Omit item with r < .3
• Construct a
• Construct b
• Construct c
Descriptive Persepsi Pelajar Terhadap Sekolah
• Jantina & Tingkatan
– Analyze > Descriptive Statistics > Frequencies > Jantina & Tingkatan
• Jantina Mengikut Tingkatan
– Analyze > Descriptive Statistics > Crosstabs > Rows (Jantina) & Column (Tingkatan)
Descriptive Persepsi Pelajar Terhadap Sekolah
• Score & percentage for each item
– Analyze > Descriptive Statistics > Frequencies > (All items)
Calculate Means (Persepsi Pelajar Terhadap Sekolah)
• Recode negative items
– Transform > Recode
– 1 5
– 2 4
– 3 3
– 4 2
– 5 1
Calculate Means (Persepsi Pelajar Terhadap Sekolah)
• Means
– Overall
– Transform > Compute variable > Target variable (MEAN) > Numeric Expression
Calculate Means (Persepsi Pelajar Terhadap Sekolah)
• Means
– Prasarana Sekolah
– Tenaga Pengajar
– Kepimpinan Sekolah
Compare Means (Persepsi Pelajar Terhadap Sekolah)
• Gender (Male, Female)
– Overall
– Prasarana Sekolah
– Tenaga Pengajar
– Kepimpinan Sekolah
T Test
• One-Sample T Test
– To compare sample mean and population mean
• Independent-Samples T Test
– To compare means of 2 different groups
• Paired-Samples T Test
– To compare means of 2 sets of data of the same independent variable
Jika Ujian Levene signifikan (p>.05), gunakan baris pertama. Jika Ujian Levene tidak signifikan (p<.05, gunakan baris kedua.
Ujian menunjukkan t(34) = .537,
p=.595 adalah tidak signifikan.
Keputusan ujian menunjukkan tidak
terdapat perbezaan skor min
persepsi terhadap sekolah yang
signifikan antara pelajar lelaki dan
pelajar perempuan
Assumptions
• Normality – The assumption of normality is a prerequisite for
many inferential statistic.
– To explore normality graphically • Histogram
• Box-plot
• Stem-and-leaf plot
– To explore normality statistically • Shapiro-Wilk statistic
• Skewness
• Kurtosis
Assumptions
• Normality (graphically)
– Analyze > Descriptive Statistics > Frequencies
– Move variable (eg Min Keseluruhan) into the Variable box.
– Click Charts >`Histogram’, `Show normal curve on histogram’
Assumptions
• Normality (statistically) – Shapiro-Wilk
– Analyze > Descriptive Statistics > Explore
– Move variable (eg Min Keseluruhan) into the Dependent List box.
– Click Plots > Normality plots with test
– If the significance level is >.05, then normality is assumed.
Assumptions
• Homogeneity of variance
– The groups should come from populations with equal variances
– Levene test
• If the test is significant (p < .05), it shows that the variances are unequal.
• If the test is not significant (p > .05), it shows that there is no significant differences between the variances of the groups.
Compare Means (Persepsi Pelajar Terhadap Sekolah)
• Tingkatan (Ting 1, Ting 2, Ting 3)
– Overall
– Prasarana Sekolah
– Tenaga Pengajar
– Kepimpinan Sekolah
Analysis of Variance
• One Way ANOVA
– To compare means of more than 2 groups of an independent variable.
– Analyze > Compare Means > One-Way ANOVA
– Options > Descriptive > Homogeneity of variance test
Analysis of Variance
• One Way ANOVA
– To compare means of more than 2 groups of an independent variable.
– Analyze > Compare Means > One-Way ANOVA
– Options > Descriptive > Homogeneity of variance test
The analysis showed that there is no statistically significant difference at the level of p < 0.05, F(2, 35) = 1.461, p = .247.
Correlation
• Relationship between 2 variables.
– Value of correlation coefficient, r: -1 < r < 1.
– r < 0 – negative correlation
– r > 0 – positive correlation
– r = 0 – no correlation
– r + 1 – perfect correlation
– R > 0.8 – strong correlation
– R < 0.5 – weak correlation
Correlation
• Relationship between 2 variables. – Pearson product-moment coefficient
• The relationship between 2 continuous variables
– Phi coefficient • The relationship between 2 categorical variables
– Point-biserial correlation • The relationship between a continuous and a
categorical variable
– Spearman’s rank-order correlation • Assumption underlying correlation cannot be met
adequately
Correlation
• Assumptions: – Related pairs: data must be collected from related
pairs
– Scale of measurement: data should be interval or ratio in nature
– Normality
– Linearity: the relationship between the 2 variables must be linear
– Homoscedasticity: the variability in scores for one variable is roughly the same at all values of the other variable
Correlation
– Normality
• Normality – Shapiro-Wilk
–Analyze > Descriptive Statistics > Explore
–Move variable into the Dependent List box.
–Click Plots > Normality plots with test
– If the significance level is >.05, then normality is assumed.
Correlation
– Linearity: the relationship between the 2 variables must be linear
– Homoscedasticity: the variability in scores for one variable is roughly the same at all values of the other variable
– Scatterplot: Graphs Legacy Dialog Scatter/Dot Simple Scatter
There is a linear relationship between pre-test and post-test
The scores cluster uniformly around the regression line, the assumption of homoscedasticity has not been violated
Correlation
Analyze Correlate Bivariate Pearson
Non-Parametric techniques
• Assumptions:
–Random sampling
–Variability across distribution
– Independence i.e. subjects appear in anly one group and the groups are not related in anyway
Non-Parametric techniques
• Mann-Whitney test
• Kruskal-Wallis test
• Spearman’s rank order correlation
• Chi-square
Non-Parametric techniques
• Chi-square
– To discover if there is relationship between 2 categorical variables
• Mann-Whitney test
- To test that 2 independent samples come from populations having the same distribution.
• Kruskal-Wallis test
– To examine differences between two or more groups.
• Spearman’s rank order correlation (Spearman rho)
– A non-parametric alternative to the parametric bivariate correlation
Chi-square
• To discover if there is relationship between 2 categorical variables
–Variable 1: Gender (Male, Female)
–Variable 2: Hometown (Kuching, Kota Kinabalu, Others Urban, Rural)
Chi-square
• Hypotheses:
–Ho: Hometown and gender are independent
–Ha: Hometown and gender are related
• Analyze Descriptive Crosstabs Statistics Chi square
Conclusion: Hometown and gender are related.