This webpage provides useful links on the statistical aspects of research.

### study designs and data collection

#### experiment

#### survey

#### observational study

#### meta-analysis

#### power and sample size calculations

### exploring data

#### variables

- What are variables?
- Descriptive statistics 1
- Descriptive statistics 2
- Variability: variance, standard deviation (SD), interquartile range (IQR)
- Sample vs population
- Standard deviation (SD) or standard error of the mean (SEM) 1
- Standard deviation (SD) or standard error of the mean (SEM) 2
- Percentiles

### dealing with missing data

- What is missing data?
- Dealing with missing values in SPSS
- Multiple imputation in SPSS
- Imputing missing values in R

### hypothesis testing / how to choose and perform a statistical test

### tests to compare...

### ...means

#### parametric tests: t-test

- About t-test: one-sample, independent-samples, paired-samples
- One-sample t-test in SPSS
- Independent-samples t-test in SPSS
- Dependent (paired) t-test in SPSS
- One function for different types of t-test in R

#### anova

#### non-parametric tests

- Nonparametric Tests for the Interaction in Two-way Factorial Designs Using R
- Parametric or non-parametric analysis

### ...survival times

#### logrank test (and kaplan-meier plot)

### evaluating dependencies

#### chi-square test of independence

#### correlation

#### decision curve analysis

### bias

### statistical softwares

- Information about R
- RStudio
- How to install R and RStudio
- Tutorials for learning R
- Intro to RStudio
- DataCamp - Learning R online
- RMarkdown cheat sheet

### glossaries

- International Statistical Institute's glossary of statistical terms in Finnish translated into multiple languages
- Statistical terms in English translated into Finnish
- Statistical terms in English, Finnish and Swedish
- Glossary of epidemiological terms English-Finnish