• Question: The 'redundancy effect' says that it is bad to read out the text of PowerPoint slides but the 'modality effect' says that 'presenting information using both auditory and visual working memory can increase capacity ... For example, when using a diagram and text to explain a concept, the written text can be communicated in spoken form' ('Cognitive Load Theory: Research the teachers really need to understand', Centre for Education Statistics and Evaluation, August 2017). These two seem to me to contradict. Have I misunderstood?

    Asked by maria e to Yvonne, Yana, Shirley, Paul, Mike, Linda, Gaia, David, Anna on 11 May 2018.
    • Photo: Yvonne Skipper

      Yvonne Skipper answered on 11 May 2018:

      Hi Marie
      I am not an expert in this area, but I would think that perhaps the answer to this is in the way you present the information. For example, if you read Powerpoint text out word for word then this may not help learning as your words are identical to those they can read. However, if you presented the slides and spoke around them, making similar points and perhaps drawing links to other knowledge this may be more beneficial as you are presenting the same information in a different way.
      Hope this helps
      Yvonne

    • Photo: Anna Kauer

      Anna Kauer answered on 21 May 2018:

      I think the issue to be aware of is that while multimodal learning can be useful, if you eg read out different words to the ones on the slides, you are asking people to pay attention to two different things at the same time – which cognitively is a very difficult thing to do. Divided attention is one of the last thing to mature at 16-18 and it remains something that we are not terribly good at even then. However if you were to present quite a short point and then speak around it, as Yvonne says, this should work fine. Depending on the age of the children you are working with, it might be less confusing for them to have very little on a slide at a time so they can deal with what they are seeing and then focus on what you are saying.

Comments

  • Photo: suehellman

    suehellman commented on :

    Hi Marie. Presenting identical information in text & auditorily does lead to cognitive overload. The audience can either process the text or listen to you (split attention). You may have experienced this with closed captions on a tv. One can either pay attention to the spoken word or read the captions. It’s very hard to attend equally to both. My advice? Keep your bullets very brief — just a few words. That will anchor what you have to say. Your audience will attend more to what you’re saying. (Personally I think a lot of speakers use text that is identical to their remarks is that it relieves them from having to learn their own presentations. They can just read.)

  • Photo: Carole

    Carole commented on :

    Hi Maria,
    Great question. To elaborate a bit on what some other folks have said, the key really is on what information you are presenting in each modality. The idea is that you have different channels in your brain that process visual and verbal information, and each of those channels has a certain capacity—so yes, making use of both of those channels means you can process more total information than just using one. The thing is, you can take in verbal information by reading it or by hearing it—so if you have text both on the screen and being spoken out loud, all that text is competing for resources in your verbal channel. Also, we read at a different pace than other people speak, which means that coordinating written and spoken information requires extra cognitive effort. If you want the learner’s focus to be on what you’re saying, then a few keywords on the screen (presented at appropriate times) can be helpful, but what’s even more helpful is a diagram or illustration of what you’re teaching. This way, the visual information supports the verbal information, and you’re making better use of both channels.