descriptive statistics

► syllabus content for the Algebra Topic: SL syllabus (see syllabus section 5.1); HL syllabus (see syllabus section 5.1).

Many students will have some prior knowledge of several of the important facts and concepts in this part of the syllabus - such as mean, median, mode, frequency tables, histograms and scatter diagrams (SL). Nevertheless a thorough coverage of descriptive statistics is very important because many of the basic concepts covered/reviewed in this part of the syllabus are essential for understanding probability distributions, specially continuous probability distributions in HL.

Something that is worth noting is that there is a significant difference between the SL syllabus and the HL syllabus in terms of the quantity of information on what should be covered for descriptive statistics. In the HL syllabus there is one syllabus section (5.1) for descriptive stats which contains only 29 words of 'content'. Whereas, the SL syllabus has three sections (5.1, 5.2 & 5.3) and contains nearly 3 times as many words to describe the 'content' for descriptive statistics. I would recommend that anyone teaching HL should refer to sections 5.1, 5.2 & 5.3 in the SL syllabus and be sure to cover all the content indicated there. For example, there is no specific mention of cumulative frequency graphs in the HL syllabus, but questions involving cumulative frequency graphs are sometimes included in HL exams. For example, the question in the 'hidden box' below was on an HL Paper 2 exam not too long ago.

question with cumulative frequency graph on an HL exam

4 questions - ‘accessible’ to ‘discriminating’

accessible SL question

moderate SL / accessible HL question

discriminating SL / moderate HL question

discriminating HL question