Memory, and why recognition beats recall

Working memory is small and decays unless rehearsed

Intuition

Read a phone number aloud, walk into the next room, and it is gone. That is working memory: a small, temporary workspace. The lecture’s memory test showed two numbers, 1300888333 and 1-800-793-864, to make the point.

Contents move to working memory from sensory memory in a fraction of a second. Working memory has three elements: the central executive for decision making, the visuo-spatial sketchpad for visual information and the articulatory loop for auditory information. Through rehearsal, which refreshes the contents, information is retained. Without rehearsal it decays.

Long-term memory has four elements and two retrieval routes

Long-term memory has four elements.

Mechanism

• Semantic: information related to meaning.
• Procedural: knowledge of how to do things, such as typing or driving.
• Episodic or autobiographical: memories of personal events or experiences, such as birthdays, graduation or getting married.
• Permastore: memories that last our lifetime.

The process has storage (encoding) and retrieval, which is recovering memories from storage. Retrieval can be by recognition or by recall. The lecture summary says recognition is easy and recall is hard.

Compare

Recognition

Pick the right item from what is shown. Example: a drop-down list, a menu, an icon.

Less effort from long-term memory and less load on working memory.

Recall

Produce the item with no cue. Example: typing a command name from memory.

Higher effort, more errors.

Design for recognition and low load

Lecture 2 gives three implications. Reduce cognitive load by avoiding long, complicated procedures. Design interfaces to promote recognition rather than recall, using familiar interaction patterns, menus, icons and consistently placed objects. Provide a variety of ways of labelling digital information so users can identify it again. This is the same idea as Nielsen’s heuristic “recognition rather than recall” and Shneiderman’s “reduce short-term memory load” from Week 1.

Exam detail

Sample exam question 14 gives the correct reasons for preferring recognition: less effort from long-term memory, less dependency on working memory, and it supports error recovery and decision-making. The wrong options claimed recall is “faster and more intuitive” and “improves user satisfaction in complex systems”.

Pitfall

Do not mix up the working memory elements with the long-term elements. Central executive, sketchpad and articulatory loop are working memory. Semantic, procedural, episodic and permastore are long-term memory. Procedural memory is “how to do things”, so typing and driving belong there, not in episodic memory.

Recall

Name the three working memory elements and the four long-term memory elements.

Working: central executive, visuo-spatial sketchpad, articulatory loop. Long-term: semantic, procedural, episodic/autobiographical, permastore.