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The 5 best theories for the IA

You MUST be link a theory to your study. Here are my recommendations.

In this post I’ll outline the five theories I think are the best to base your experiment on. I’ll suggest some good studies that go with those theories. 

We always think about the IA based on the key study being replicated. But since the most important thing is the background theory or model, maybe that’s a better place to start.

The Five Best Theories

In examining the IA, these are the theories (or models) that are consistently used effectively in top-scoring IAs. That’s not to say you can’t do well with other theories. As always, consult your teacher and seek their advice.

These theories have the added advantage of being used in the IB Psychology course, so you’ll be able to use them (and by default the original study) in your IB exams.

In alphabetical order, the best theories for the IA are:

The following summaries are brief outlines only. Use these to choose one that you think is interesting. You can find more details about the recommended studies on this blog post.

Don’t care? Then I recommend Schema Theory and Bransford and Johnson. It’s the easiest for multiple reasons. 


Dual processing model (Kahnemann and Tverskey)

This is a model of thinking and decision making that posits we have two main systems of thinking: system one (fast) and system two (slow). Relying on system one can lead to cognitive biases, such as the anchoring effect. People often use system one when relying on heuristics to make judgements and decisions.

Your IA is likely studying a cognitive process. You need to understand how a theory explains that process.

Relevant studies:


Levels of processing model (Craik and Lockhart)

This model posits that we process information based on different levels (deep or shallow) and this influences memory. Information processed deeply leads to better memory than shallow processing.

Relevant studies:


Multi-store model (Atkinson and Shiffrin)

This model of memory describes how memories are formed. Information travels between three stores (sensory to short-term to long-term) and these stores differ in terms of duration and capacity. Information flows between them based on control processes (attention, rehearsal, retrieval).

Relevant studies:


Schema theory (Bartlett (and others))

Avoid Bartlett’s War of the Ghosts. It’s a troubled study from start to finish and is not good for the IA.

This theory posits that our mind organizes our knowledge and memories into clusters called schemas. These schemas can influence how we process, interpret and remember information.

Relevant studies:


Working memory model (Baddeley and Hitch)

This model elaborated on the short-term store of memory proposed by the MSM. It describes how information in our working memory is processed. The central executive controls the flow of information into our slaves systems – the visuospatial sketchpad (visual working memory) and our phonological loop (auditory working memory). If one slave system is overwhelmed it can affect our working memory.

Relevant studies:


Got a good recommendation? Pop it in the comments.

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