One method to rule them allThe importance of experiments in IB Psychology

There are over 200 possible essay questions in Paper 1. This creates a lot of anxiety. But there’s a simple way to go into Paper 1 exams with confidence – take the one ring to rule them all – EXPERIMENTS!

The experimental method includes true, quasi and field experiments. Every topic in the IB Psychology course can be studied with at least one of these kinds of experiments. If you can explain this, you’re prepared for any concept. Let’s first look at how experiments are relevant to the concepts. For simplicities sake, I’ve focused mainly on true/lab experiments.

Jump to…

• Study tips
• Teacher tips

Causality 

True experiments are the only way we can establish causality in psychology. More specifically, randomised, placebo-controlled, doubel-blind experiments are the “gold standard” in experimental research.

What but if we can’t run a true experiment? For instance, we can’t randomly allocated to be collectivistic or individualistic. This is where we can describe the use of quasi-experiments instead – a method that “…resembles a true experiment but lacks random assignment of participants to different groups.” (IB Guide pg. 67). Now we can run the experiment, but because we haven’t ranodmly allocated participants we cannot make claims about causality.

Change

Change is at the very heart of true experiments. First, they’re designed to see how one variable changes another (the IV changing the DV). We can phrase this another way – they measure how specific variables can change behaviour. For example, Asch’s famous conformity experiments studied how group size can change conformity levels.

Change can also be the enemy of a good experiment – we want constancy, not change. The famous phrase “ceteris paribus” (meaning”other things equal”) is the core of good experiment design – we want everything to be equal (i.e. unchanged) except the independent variable. For example, if we study the effects of a new drug on depression, we want our participants to be as similar as possible except one takes the drug and the other a placebo.

The final way change is relevant to experiments is we can use the findings to create interventions to help change human behaviour for the better. If experiments find what causes harmful behaviour, we can design programmes to target that cause. The same goes for experiments on positive behaviour. For example, experiments on the positive benefits of nutritional supplements in prisons can be used to develop nutrition programmes and guidelines for other prisons.

Measurement

The dependent variable in an experiment must be measured. How and how accurately it’s measured is a massive consideration in experimental research. There are a range of factors that can influence the validity of the measurement of the dependent variable, including placebo effect and researcher bias. We also measure averages and statistical significance.

Bias 

Experiments test hypotheses. A hypothesis is a prediction. But if we think we know what’s going to happen, won’t that lead to confirmation bias? This is one way researcher bias can reduce the validity of an experiment. The placebo effect is also a type of bias which must be controlled in a good experiment.

Perspective

Experiments are reductionism by their nature – they mostly measure the effect of a single independent variable on a single dependent variable. But if we’re trying to understand complex human behaviours, like love, aggression, morality or addiction, this gives us a limited perspective.

Experiments also adopt different approaches. Alternatively, researchers from different approaches (i.e. perspectives) adopt experiments to test their theories.

Responsibility 

Experiments are conducted because we’re expecting an effect. This means we’re expecting some kind of change in human behaviour. This creates the risk of harm and the golden rule of responsible research is “do no harm.” For example, if you have a placebo group in an experiment on treatments for PTSD then participants in that group won’t be getting a treatment. Similarly, animal experiments in biological psychology regularly cause harm. How can we be responsible while at the same time killing animals for research?

Psychologists often balance responsibility with validity – sometimes to increase validity they have to breach certain guidelines, but if they maintain responsible standards then their validity might be jeopardised. For example, if you reveal too much information in your informed consent form it might be a demand characteristic that causes participant expectancy effects. If you run a carefully controlled animal experiment you have rats in isolated cages. There are no perfect solutions, only trade-offs.

Studies vs Research: We don’t need specific studies in essays. But I maintain you should discuss research – whether that’s general procedures or difficulties with research methods for certain topics. The best answers will describe commonly used research experimental and/or correlational procedures used to study the topic, how and why they’re used and how they’re relevant to the concept.

Study tips

• Master the key terms: of all the methods, experiments have the most key terms. Things like placebo-controls, random allocation, independent samples and extraneous variables are just some of the key terms you should know.
• Memorisation vs Application: You can memorise specific experiments. For some topics this makes sense, like knowing the bobo doll experiment for social learning theory or simple anchoring bias experiments. For topics that don’t have memorable experiments, practice describing how an experiment could be conducted instead. Even better find out how experiments are commonly used for that topic.
• How to Practice: Go to this blog post, choose a context, spin a wheel, then write down how experiments are (or could be) used to study that topic. If you find this too difficult, you need to go back and revise the key terms and process in an experiment.

Teacher tips

• If I were you…The above example shows that a little knowledge goes a long way with the concepts. If we teach a few things really well, our students will be well-prepared. It’s easy for me to give advice since I currently don’t have my own classes. All my advice is easier said than done – I’m just going on my hunches. But my hunch is the more I discuss concepts in class the more I’d be draining the joy out of my lessons and confusing the students (and myself). I would be saving the concepts for specific standalone lessons (e.g. in a research methods unit) and during exam-revision specific lessons. Draw a line in the sand – the lesson is about content or concepts. The exception, of course, if using the concepts as critical thinking exercises.

I hope this helps.