seminare 2

• The structure of a research

  1. Variables and types of variables

  2. Research Questions

  3. Hypothesis

  4. Causality

  5. Papaja
• Research Question


  A good research question should be:

  1. Clear – meaning and purpose are easy to understand

  2. Concise – the topic is presented in a limited number of words („few words does wonder")

  3. Specific –it refers to a concrete problem that can be properly addressed in a specific place and with the resources allocated.

  4. Complex – requires broad answers (not dichotomous, like "yes" or "no")

  5. Debatable – the answers may be diverse, complex, and subject to further analysis and debate
• PICO Criteria


  • P: Problem/Patient/Population
  • I: Intervention
  • C: Comparison/Control
  • O: Outcome
• Hypothesis


  We know that a hypothesis is good if:

  1. Can be tested

  2. It's falsifiable

  3. It's formulated in a simple manner (parsimonious)

  4. It's precise (specificity)

  5. Has scientific utility
• Causality (Mill's Model)


  1. There is an association between the cause and the effect

  2. The cause should appear before the effect (temporality)

  3. Lack of alternative explanations
• Types of causal relation

  • Necessary and sufficient (X and Y inseparable)
  • Necessary but not sufficient (X is not sufficient for Y)
  • Sufficient, but not necessary (in addition to X, Y can be the result of other factors as well)
  • Neither sufficient nor necessary (X cannot cause Y alone)
• Hill's model (1965) – for the relationship between exposure and illness


  • Strength of association – a high association between exposure and disease = a higher probability of a causal effect
  • Consistency – greater likelihood of a causal relationship when there is replicability
  • Specificity – if the relationships are specific then increased likelihood of a causal relationship (BUT specific relationships are hard to capture – usually no harm comes alone)
  • Temporality – cause before effect
  • The biological slope – if there is an increase the exposure, there is also an increase in the probability of a disease
  • Plausibility – the existence of explanatory mechanisms (biological, social, psychological)
  • Coherence – a reference to the literature
  • Experiment – results obtained from experiments
  • Analogy – when there are robust results, less robust results "could be more easily accepted".
• Papaja


  1. Bonus for papaja and zotero

  2. Steps for adding the add-on for Zotero

  3. Other recommendations
• Example of exam question

  • What does it mean for a scientific hypothesis to be parsimonious?

  A. It should be as complex as possible.

  B. It should be as simple and straightforward as possible.

  C. It should be based on personal beliefs or opinions.

  D. It should be able to be proven false if it is not supported by the evidence.