Readability of South African Constitutions

South Africa has had five constitutions during its history. The first one, the South Africa Act of 1909 was actually an act of the British Parliament. The 1961 Constitution was adopted during apartheid to transform the country into a Republic and the 1983 tried to reform things a bit with a Tricameral parliament. The 1993 Constitution was an interim one that set out the framework for the process that created the current, democratic Constitution of 1996.

My thesis looked at the readability (and factors affecting easy comprehension) of South African Constitutions at two specific points in time, but it is quite, or even more interesting to look at the whole developmental sequence.


What the chart shows is the length of the constitutions, the average number of words in its sentences and the SMOG index, which tries to estimate the number of years of formal education needed to understand the text.

There is a quite visible trend of the constitution getting longer as it becomes more democratic, probably as a result of the need to provide clear guidance in issues that were previously simply decided by the government in their own authority. The extra text of the 1993 constitution was not added in the form of easy to understand, short sentences, as the average sentence length of 50 words shows. Conscious attempt to make the text more comprehensible came with the 1996 Constitution, which resulted in cutting on average 20 words from every sentence (coming close to the average of 20-25 words in a sentence recommended by Plain Language guides).

Legal texts are by their very nature difficult to read, and combined with the long sentences, the readability scores predict that at least 18-20 years of education is needed to understand them on first reading. (This formula doesn't reflect the lexical and grammatical changes that were intended to make the text easier to comprehend.)

The South African Constitution has gone full circle in 90 years, in terms of readability scores and sentence length; but the similar drafting techniques describe completely different realities.