Thank Me With TEA!

Research Methods – Variables & Measures

Resources

The Breakdown

Here is a summary of the week 2 material based on the provided sources:

Important

  • Scientific Method – This course relies on the scientific method, which is a process of systematically collecting and evaluating evidence to test ideas and answer questions. It is based on systematic empiricism, empirical questions, and public knowledge.
  • True Zero – It is very important to understand what a true zero means in measurement. This occurs when a score of zero represents the complete absence of the variable being measured. Measures in psychology and education typically lack a true zero.
  • Acceptable reliability coefficient – A numerical value used to assess the consistency of a measure. Keeping in mind that a threshold of .70 and above is considered an acceptable level for a reliability coefficient is very important.
  • Identifying missing information in operational definition – You will have this kind of question where you need to identify what information is missing from an operational definition. A complete operational definition describes how a construct is measured and includes the measure name, number of items, what it measures, response format, scoring, and information about its validity and reliability.
  • Goals of Science – It is very important, especially for the midterm, to understand the three primary goals of science. These goals are to describe phenomena, to predict future events or conditions based on patterns, and to explain why phenomena occur by developing theories.

Core concepts

  • Science – Defined as a general approach to understanding the natural world. Psychology uses this same approach to understand human behaviour.
  • Fundamental Features of Science – Science is characterised by three fundamental features: systematic empiricism (relying on observation), empirical questions (testable through observation), and public knowledge (sharing research findings).
  • Systematic Empiricism – Involves making careful observations, often under controlled conditions, to test ideas and using rationalism to draw valid conclusions.
  • Empirical Questions – These are questions that are possible to answer by making systematic observations.
  • Public Knowledge – Scientists make their findings public, typically by publishing them in research literature, so others can learn from and build upon them.
  • Model of Scientific Research in Psychology – Research typically follows a cyclical model: a research question leads to an empirical study, the data are analysed, conclusions are drawn, and the results are published, which can then lead to new questions. Questions can also arise from observations or practical problems.
  • Research Literature – Comprises all published research in a field, mainly journal articles and scholarly books. Reviewing it helps refine research questions and identify methods.
  • Research Question – An empirically testable question focusing on a single variable or the relationship between variables, forming the basis for a study.
  • Hypothesis – A specific prediction derived from a theory or existing evidence about what should be observed in a particular study.
  • Theory Testing – Researchers often use the hypothetico-deductive method, starting with a theory to derive a hypothesis, testing it empirically, and then revising the theory based on the results.
  • Variable – A characteristic, number, or quantity that can be measured or observed and takes on different values.
  • Types of Variables (General) – Variables can be quantitative, where numerical scores are assigned (e.g., age, depression score), or qualitative (or categorical), where observations are grouped into categories (e.g., gender, marital status). Discrete quantitative variables are limited to whole numbers.
  • Variable Types (Research Context) – Include the independent variable (manipulated or predictor), the dependent variable (the outcome that is measured), and confounding variables (extraneous variables that could affect the dependent variable) [39, 109, 16:52 Week2].
  • Psychological Construct – An abstract concept that cannot be directly observed (like depression, anxiety, or love) and must be measured indirectly through related behaviours or symptoms.
  • Conceptual Definition – Provides a description of a psychological construct based on theory and literature, defining what it means.
  • Operational Definition – Specifies exactly how a psychological construct will be measured in a particular study, detailing the methods and tools used. Measurement can involve self-report, behavioural observation, or physiological measures.
  • Levels of Measurement – Different scales used to classify variables: Nominal (categories only), Ordinal (ranked categories), Interval (scores with equal intervals but no true zero), and Ratio (scores with equal intervals and a true zero).
  • Reliability – Refers to the consistency of a measure over time, between different raters, or among the items within the measure itself.
  • Validity – Refers to the accuracy of a measure; whether it measures what it is intended to measure. Types include face validity (appears valid), content validity (covers all aspects of the construct), and discriminant validity (distinct from unrelated constructs).
  • Converging Operations – Using multiple different measurement methods (e.g., self-report and physiological) to assess the same construct.
  • APA Style – A set of guidelines for writing in psychology that standardizes the organization and formatting of research reports to promote clear scientific communication. Standard sections of an empirical report include the Abstract, Introduction, Method, Results, Discussion, and References.