Final answer:
It's best to learn a moderate amount of new words each day, such as three to five, to ensure effective retention and avoid the rapid information decay noted by Ebbinghaus's research. This approach is consistent with the natural language acquisition observed in children and encourages steady, long-term learning.
Step-by-step explanation:
When learning new words for a test, it's not just about the number you aim to learn each day but also how effectively you can retain and recall those words. Based on the research analyzed by Hermann Ebbinghaus, your memory for new information decays quickly; an average person will lose 50% of memorized information after 20 minutes and 70% after 24 hours.
Children's vocabulary expansion during the early years provides insight into the natural pace of language acquisition. For example, five-year-old children have a vocabulary of at least 1,500 words and are capable of learning new words through various cognitive developments.