The committee Bloom chaired did not include this rung as it can be confused with the higher level understanding we are aiming for higher up the ladder. It was included in later versions to make the point that factual knowledge devoid of any context is a bit pointless! Someone who can both recall that 2+2=4 AND understands that this is a sum showing how you add up numbers is clearly at a higher level than someone who can just recite the fact.
To check understanding, teachers often use CLOSE exercises or COMPREHENSION tasks which involve the key words being hidden in a paragraph or mixed up and needing sorting. These are generally attempts to check the learner is engaging with the content. They still may not actually understand what they are answering but they do know at least one context for the knowledge they have been given.
I once saw a teacher ask a class to write in their books that ‘Global warming is the gradual increase in temperature around the globe’. They then conducted a lesson about Global warming and at the end, conducted a check to see if the class had understood the term ‘Global warming’. They asked the question – what is ‘Global warming’ but none of the multiple choice options were the definition the class had been given. They had to choose from ‘The Earth getting warmer’, ‘Everyone being ready’, ‘Damaging the Ozone Layer’, ‘Carbon Dioxide’, ‘Pollution’. Only one third of the class gave the right answer yet earlier all of the class had correctly matched the term with the definition they had been given.
Checking for this basic level of understanding is critical to confirming that a fact is known.
As there are right answers and learned responses, this rung is still highly accessible to all abilities and can be used to boost self belief. In the work by Anna Hazeldine, she tried taking learners with low self esteem and pre-teaching them the key terms and checking understanding prior to a lesson, so that when these terms came up in the lesson, the learners would feel confident to answer questions. The work led to a dramatic increase in the performance of the learners and their belief in themselves.
Questions such as ‘Why..’ and ‘Explain…’ and ‘Which…’ require some understanding as does requiring learners to write out answers in their own words.