# Mark Lansdale **Mark W. Lansdale** (born 1953 in Birmingham) is a British psychologist who works on memory and human-computer interaction. He earned his PhD in experimental psychology at the University of Cambridge (1979), then held professorships at Loughborough University, Nottingham Trent University and the University of Leicester, where he headed the School of Psychology. While at Leicester, he was part of the Greyfriars research team that located the burial site of Richard III, and he later co-wrote a psychological profile of the king. ## His PIM research In 1988, while at Loughborough, he published "The psychology of personal information management", one of the founding papers of [[Personal Information Management (PIM)|personal information management]]. His point: automating information management is mostly a psychological problem, and it comes down to three processes: recall, recognition and categorization. - **Categorizing is hard.** Items often fit several categories, or none clearly, so filing decisions are ambiguous - **Recall is the bottleneck.** People often can't remember the category they used when they filed something. Recognizing an item when you see it is easy; producing the right label from memory is not - **So systems should let you retrieve by the attributes you actually remember**, and by several of them, instead of forcing you to recall one category chosen months earlier A follow-up study with M. P. Simpson and T. R. M. Stroud (1990) looked at "enriching" documents with extra attributes (words or icons) that act as external memory aids. The results showed a strong trend: recall was higher when people chose their own attributes than when the system assigned them. Whether the attribute was a word or an icon didn't matter much; what mattered was how well it fit the document in the person's own mind. ## Why it matters for PKM Use your own words in titles, aliases and tags, not a taxonomy borrowed from someone else. A label you chose yourself is a label you have a chance of remembering. It's the [[Encoding specificity principle|encoding specificity principle]] at work: a cue you generated while encoding the note is much more likely to match the cue you'll have in mind when you search for it. It's also why I'm wary of elaborate category trees. If you won't remember the category when you search, the category is useless for finding (though it can still help for browsing, since browsing relies on recognition, not recall). ## Recent Activity - ## Insights - Retrieval usually fails at recall: people can't remember the category they used - Self-chosen attributes are recalled better than assigned ones ## Quotes <!-- QueryToSerialize: LIST FROM #type/quote AND [[]] WHERE public_note = true SORT file.name ASC --> ## Books <!-- QueryToSerialize: LIST FROM #type/book AND [[]] WHERE public_note = true SORT file.name ASC --> ## Media <!-- QueryToSerialize: LIST FROM #type/media AND [[]] WHERE public_note = true SORT file.name ASC --> ## Appears in <!-- QueryToSerialize: LIST FROM #type/media WHERE contains(cast, this.file.name) AND public_note = true SORT release_date DESC --> ## Related - [[Personal Information Management (PIM)]] - [[Encoding specificity principle]] - [[Thomas Malone]] - [[William Jones]] - [[Findability]] - [[The Complete Guide to Obsidian Search - Find Any Note When You Need It (Article)]] - [[Why You Can't Find Your Notes - The Science of Re-finding Information (Article)]] ## References - Lansdale, M. W. (1988). The psychology of personal information management. *Applied Ergonomics*, 19(1), 55-66. https://doi.org/10.1016/0003-6870(88)90199-8 - Lansdale, M. W., Simpson, M., & Stroud, T. R. M. (1990). A comparison of words and icons as external memory aids in an information retrieval task. *Behaviour & Information Technology*, 9(2), 111-131. https://doi.org/10.1080/01449299008924229 - Wikipedia (German): https://de.wikipedia.org/wiki/Mark_Lansdale - Author bio, *The Psychology of Richard III*: https://www.amazon.co.uk/dp/1913551938 - Affiliations (OpenAlex): https://openalex.org/A5111704514