• An approach to explore and describe a culture, subculture or social group
• Researchers become a part of the culture or group they are investigating
• Methods can be quantitative or qualitative

• method of collecting in the moment or reflective qualitative data
• typically a longitudinal approach
• ease of completion results in low attrition rates
• can be recorded on mobile phones for easy accessibility

Classical test theory is the most commonly used approach to psychometrics and considers test scores the result of a true score combined with measurement error.

Machine learning occurs when computers learn from data to make predictions in new, previously unseen data.

AI is concerned with the automation of decision making and pattern recognition

Given appropriate data, it is sometimes possible to derive causal inferences from observational (non-experimental) data

Rasch analysis can be used to derive an interval metric from psychological assessments, though is based on strong assumptions.

IRT models test and item properties in a probabilistic manner