I'm planning a study on memorability of episodic events. Therefore, participants record a couple of hours of their daily life using an egocentric camera (encoding). After a certain time, they are shown snippets from the recording and judge whether they remember it or not (decoding).

I don't have a psychological background, hence I have some questions:

  • How long should the snippets be? Currently, we have 5sec videos, separated by 10sec margin. I know chunking, however, it happens in encoding phase, I'm looking for an equivalent in decoding.
  • Maybe showing a few frames from the video is better than playing video?
  • How long should the time between encoding and decoding be? Currently, it's 6 to 8 days. I'm aware of Time Scale Similarity.
  • I've found a work that suggests that asking people whether they remember or not is sensible. However, any further evidence would be great.
  • I think Experiences of Remembering, Knowing, and Guessing is also highly related.

As this is a scientific work, references are highly appreciated.

  • 2
    $\begingroup$ Hi Pasbi, welcome at CogSci. An excellent question you've got there! I'm looking forward to an answer :) $\endgroup$ Jun 23, 2017 at 8:09
  • $\begingroup$ see also psycnet.apa.org/… $\endgroup$
    – pasbi
    Jun 23, 2017 at 8:10
  • $\begingroup$ Consider that time is a variable that affects retreival (Power law of forgetting). Also one or two frames is enough to be used as a cue, use the video only to test the accuracy of the recall. $\endgroup$ Jun 23, 2017 at 9:21
  • $\begingroup$ When I show frames, I need to select them somehow. Since I use egocentric videos, it is likely that they are of bad quality (e.g. blurry). How do you propose to test accuracy? $\endgroup$
    – pasbi
    Jun 26, 2017 at 7:34
  • $\begingroup$ You need to do the dirty work first and get started searching for and reading papers in psychology and neuroscience. As you seem to be aware, your experiment should be rooted in the scientific literature. Ask a librarian how to search and what resources are available. If you are lucky, you will have access to Web of Knowledge. EBSCOHost also works sometimes as does APAs PsycNET. Locate the latest and the most cited research. $\endgroup$
    – noumenal
    Jul 15, 2017 at 19:24

2 Answers 2


The answers to your questions in your post would depend on the scope of your study. For example, with

How long should the time between encoding and decoding be?

it would depend on what criteria is set within the scope of the study. If the people who are asking you to perform the study are asking for specific timescales then you need to stick to them and outline that in your report.

If however you have freedom to do so, as you seem to be asking on a psychological standpoint, it may be beneficial to test different timescales and maybe tabulate the results of memorability against time. You could even test different timescales against different ranges of emotional levels attached to the event.

For example,

does a person remember a highly emotional episodic memory longer than a non-emotional one?

What about medium levels of emotions?

You could also add to this with your question on how long snippets should be.

Does a 5sec video snippet help someone to remember better than a single frame image?

If you have the time and freedom to explore, you can conduct a large amount of research on memory. It would only be down to how wide you can make the scope of the study whilst keeping it within the remit of what you are trying to find out.


Episodic memory is probably the most complicated kind of memory, and a lot of these parameters are going to vary in interesting ways - for example, playing a video may result in better recall (what you call "decoding") because it preserves the temporal context of the memory. These things are interesting, and the way you treat them depends entirely on the specific question you are interested in asking.

There's a lot of parameters here that you're going to want to just test out (and report the results of in your paper!).

However, I want to leave you with a study that may help guide your thinking. These authors did something similar, but were more interested in the neurophysiology - you might find some helpful context.


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