Baddeley and Hitch proposed in 1974 that short-term memory has different forms, in a model called:

1. The simple stage model treats short-term memory as a single store. 2. Baddeley and Hitch in 1974 proposed a working memory model. 3. In that model short-term memory has different forms rather than one. 4. The name working memory emphasises that the store is used, not merely held. _Source: OpenStax Psychology 2e (CC BY 4.0), Ch 8 'Memory', sections 8.1-8.4_