Find 5 psychology sources about the spacing effect, which has to do with how the study of (or exposure to) material is scheduled (either crammed together or spread out). What were the materials used?

Find 5 psychology sources about the spacing effect, which has to do with how the study of (or exposure to) material is scheduled (either crammed together or spread out). And summarized what their research question, method, result. Remember to also answer the following question: 1. How many conditions and what were they?2. What were the materials used? (words lists? Paragraph text? etc.)3. What was the test format? (multiple choice? Word pairs? Open response?)4. How long between study and test? (sometimes called the “retention interval”)5. What kind of participants? (college, high school, MTurk, etc.)