The next topic is that of ‘that of’
This is a low-frequency vocabulary item and is likely to get you a high score for Lexical Resource (vocabulary) in IELTS. However, you need to be sure to use it appropriately.
than that of (comparing possessives)
- Their position was only slightly better than that of slaves.
- (= Their position was only slightly better than the position of slaves.)
- Their hearing is no better than that of humans.
- (= Their hearing is no better than the hearing of humans.)
- The literacy rate of males is considerably higher than that of women.
- (= The literacy rate of males is considerably higher than the literacy rate of women.)
- (as shown) each of these sentences could just as easily be written without using that of, but that of makes the sentences appear more sophisticated.
- the nouns being compared – position, hearing, literacy rate – are all abstract.
- that of helps to avoid repetition, which might be useful when the nouns being compared are part of a longer noun phrase:
- The average increase in global surface temperature this year has been slightly higher than that of last year.
- (= The average increase in global surface temperature this year has been slightly higher than the average increase in global surface temperature last year.)
is/was that of (introducing important topics)
- Another interesting point is that of education.
- (= Another interesting point is education.)
- Another key concern was that of accountability.
- (= Another key concern was accountability.)
- The primary problem here is that of copyright.
- (= The primary problem here is copyright.)
- (as shown) each of these examples could easily be written without that of, but that of looks more sophisticated.
- that of introduces a distinct topic requiring analysis and discussion.
- the nouns being introduced – education, accountability, copyright – are all abstract.
is/was that of (highlighting essential features)
- The principal role was that of the dying person.
- (= The most essential feature of the role was – dying person).
- His voice was that of a breaking man.
- (= His voice most closely resembled – the voice of a breaking man.)
- The body was that of a female.
- (= Despite some ambiguities or non-standard representation, the body most closely resembled – a female.)
Again, that of is a low frequency item. I am a native English speaker and I only use that of to avoid repetition in comparatives. I suggest you think about this use next time you are comparing statistics in IELTS Task 1 writing, where there are likely to be long noun phrases that you want to avoid repeating. Good luck!