Pocket money
This resource can be used to provide evidence of students' ability to "Identify patterns in data" and explain their reasoning.
For more information see http://nzcurriculum.tki.org.nz/Keycompetencies
Correct answer  Y6 (10/2013)*  
a)  Room 4  moderate 
b) 
Response based on the shape of the graph
or

difficult 
Based on an online sample of 68 Y6 students in OctNov 2013.
The big idea behind this question is where most of the data in a graph lies (i.e., the shape or distribution of the graph). Interpreting statistical graphics is far more than identifying single features of a graph.
Students need to look at what the graph is showing overall. In this case, students are asked to identify where most of the data lies, i.e. where "the biggest chunk" of the data is.
Common error  Next steps 
Confuses the sample size (number of children in the class) with the amount of pocket money Examples: [Room 5] There were more dots on the Room 5 chart than the Room 4's chart. [Room 5] Room 4 has 23 [dots and] Room 5 has 24. 
It may be helpful to ask these students "How many children are there in Rooms 4 and 5?". Get them to read Jason's statement again. Help them see that the question is about the amount of pocket money, not the number of children in the class. If students still cannot interpret the statements or the graph, they may need to construct some dot plots of their own. 
Comments about individual features of the graph Examples: [Room 5] In Room 4 only 1 person got $6+ and in Room 5, 2 people got $6+. [Room 5] Room 5 usually has at least two people with 6 dollars or more. 
Students need to see the "big picture" of the graph, rather than looking at individual features. Get students to put a circle around most of the data ($3$5 for Room 4 and $1 $3 for Room 5). 
Makes no comments for Question b) 
Students may feel that an explaining is not important.
Get these students to explain their answer in a small group, pairs or to you individually.
Then get them to write down their oral explanation. 