Statistics guides
Statistics guides
Long-form guides written and reviewed by named statisticians. Each one covers the method properly — worked examples, assumptions, common mistakes and how to report it — rather than summarising a textbook.
Each guide is written and reviewed by one of five named statisticians holding UK doctorates, and the reviewer is credited on the page along with the date it was last checked. Guides include worked examples calculated step by step rather than summaries of textbook definitions.
Latest guide
Thematic analysis
Braun and Clarke's six phases, a worked coding example from extract to theme, the three variants compared, and how to write it up.
4,000 words · Elaine HalliburtonQualitative methods
Analysing interviews, focus groups and open text.
Thematic analysis
Braun and Clarke's six phases, a worked coding example from extract to theme, the three variants compared, and how to write it up.
4,000 words · Elaine HalliburtonPublishedContent analysis
Manifest and latent content, building and testing a coding frame, a worked example with counts, and inter-coder reliability.
3,000 words · Elaine HalliburtonPublishedGrounded theory
The three schools, open, axial and selective coding, theoretical sampling and saturation, memos, and what examiners check.
3,000 words · Elaine HalliburtonPublishedDiscourse analysis
The approaches compared, what to look for in a transcript, a worked extract analysed line by line, and rigour without reliability coefficients.
3,000 words · Elaine HalliburtonPublishedReliability and validity
Every type of each, which statistic to report, thresholds, establishing them in your own study, and the qualitative equivalents.
3,000 words · Elaine HalliburtonStatistical tests
Choosing, running and reporting the right test.
T-tests
The three types, assumptions and what to do when they fail, three worked examples calculated by hand, effect sizes and APA reporting.
3,000 words · Hafiz Ahmad TariqPublishedChi-square test
Goodness of fit and independence, the expected-count rule, a worked contingency table, Cramer's V and adjusted residuals.
3,000 words · Hafiz Ahmad TariqPublishedANOVA
How variance is partitioned, a one-way ANOVA by hand, Welch's alternative, post-hoc tests and eta squared.
3,000 words · Hafiz Ahmad TariqPublishedMann-Whitney U test
When to use it over a t-test, what it really tests, U calculated by hand, ties and effect sizes.
3,000 words · Hafiz Ahmad TariqPublishedCorrelation
Pearson, Spearman and Kendall compared, r calculated by hand, partial correlation, r squared, and why correlation is not causation.
3,000 words · Hafiz Ahmad TariqPublishedLogistic regression
Why linear regression fails on binary outcomes, odds and log odds, interpreting odds ratios, separation and sample size.
3,000 words · Hafiz Ahmad TariqPublishedRegression analysis
Simple regression worked by hand, interpreting coefficients, R squared, what 'controlling for' means, and residual diagnostics.
3,000 words · Hafiz Ahmad TariqPublishedKruskal-Wallis
The rank-based alternative to ANOVA, H calculated by hand, Dunn's post-hoc test and epsilon squared.
3,000 words · Hafiz Ahmad TariqDesign and power
Getting the study right before data collection.
The null hypothesis
Writing H0 and H1 correctly across designs, one- versus two-tailed, Type I and II errors, and why you never accept the null.
3,000 words · Hafiz Ahmad TariqPublishedExperimental design
Between and within designs, randomisation and concealment, control conditions, counterbalancing, blinding, threats to validity and sample size.
3,000 words · Hafiz Ahmad TariqPublishedHypothesis testing
The five steps in order, stating hypotheses, choosing the test, a worked example start to finish, and the errors you trade off.
3,000 words · Hafiz Ahmad TariqEvidence synthesis
Combining findings across studies.
Meta-analysis
Inverse-variance weighting worked by hand, fixed versus random effects, heterogeneity and publication bias.
3,000 words · Hafiz Ahmad TariqPublishedSystematic reviews
PICO, protocol registration, search strategy, two-stage screening, risk of bias, synthesis and PRISMA 2020.
3,000 words · Hafiz Ahmad TariqPublishedForest plots
Every element explained, why the squares differ in size, judging heterogeneity by eye, and the common misreadings.
3,000 words · Hafiz Ahmad TariqClinical and epidemiological
Effect measures for binary and time-to-event outcomes.
Reporting and data quality
Turning output into defensible write-up.
P-values
What a p-value measures, five wrong interpretations, why .05 is arbitrary, p-hacking and what to report instead.
3,000 words · Hafiz Ahmad TariqPublishedConfidence intervals
What 95% confidence actually means, intervals for means and proportions worked by hand, intervals for differences, and why they beat a p-value.
3,200 words · Hafiz Ahmad TariqPublishedNormality and Shapiro-Wilk
Why the Shapiro-Wilk p-value misleads at both ends, reading a Q-Q plot, which tests need normality, and what to do when it fails.
3,000 words · Hafiz Ahmad TariqPublishedData cleaning
A defensible workflow, validity checks, the missingness mechanisms, outlier decisions, reverse scoring and reproducible documentation.
3,000 words · Hafiz Ahmad TariqPublishedLikert scales
Item versus scale, how many points, the ordinal-interval argument settled, Cronbach's alpha, response bias and honest charting.
3,000 words · Hafiz Ahmad TariqMore guides are published regularly. Each is reviewed by a named statistician and dated, so you can see when it was last checked.
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Software walkthroughs
Doing it in SPSS, NVivo and R.
How to test for normality in SPSS
The Explore click path, reading Shapiro-Wilk, Q-Q plots, and what to do when the assumption fails.
1,800 words · Hafiz Ahmad TariqPublishedHow to run a chi-square test in SPSS
Crosstabs step by step, the expected-count check, Cramer's V and adjusted residuals.
1,900 words · Hafiz Ahmad TariqPublishedCronbach's alpha in SPSS
Reliability Analysis, the item-total table, fixing reverse-scored items and what alpha misses.
1,500 words · Elaine HalliburtonPublishedMultiple regression in SPSS
The diagnostics that are off by default, VIF, dummy coding and APA reporting.
1,300 words · Hafiz Ahmad TariqPublishedDescriptive statistics in SPSS
Which of the three dialogs to use, where the median hides, and mean versus median.
1,200 words · Hafiz Ahmad TariqPublishedHow to use NVivo
Projects, sources, nodes and coding — what NVivo does and does not do for your analysis.
1,900 words · Elaine HalliburtonPublishedCoding in NVivo
Naming codes that survive to transcript thirty, when to build a hierarchy, coding stripes.
1,400 words · Elaine HalliburtonPublishedNVivo for thematic analysis
Braun and Clarke's six phases mapped onto what you actually click, and where NVivo misleads.
1,500 words · Elaine HalliburtonPublishedHow to run ANOVA in R
One-way, two-way and repeated measures with working code, Type III sums of squares and post-hoc tests.
1,300 words · Hafiz Ahmad Tariq