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CBA 2 Information & Guide


In 3rd Year, Junior Cycle students are expected to complete their second Classroom Based Assessment (CBA) in maths.

On this page, we will detail what this CBA is, how to approach it and how it will be assessed.


Any statement in quotation marks below is taken from the official guidelines.

2023/24 Arrangements

Current 3rd Years are only required to complete a minimum of one CBA. Details here.

Additionally, members gain access to examples of completed CBAs.

What are CBAs?

In total, Junior Cycle Maths students are officially assessed in four different ways.

1) Classroom Based Assessment 1 (CBA 1) (2nd Year)

2) Classroom Based Assessment 2 (CBA 2) (3rd Year)

3) Assessment Task (AT) (3rd Year)

4) Final Examination (3rd Year)

Only the last two count towards the actual final grade of each student – 10% for the assessment task and 90% for the final examination.

The primary purpose of both CBAs, on the other hand, is to build up an understanding of the ability of each student. This information is beneficial to teachers, parents/guardians and the students themselves as it provides information as to how closely their expected level of achievement will match with their actual level of achievement.

What is CBA 2?

CBA 2 involves creating a report about a statistical investigation.

Specifically, the description of this CBA is as follows.

“A student will, over a three-week period, follow the statistical enquiry cycle.

What is the “statistical enquiry cycle”?

The statistical enquiry cycle is composed of the following four parts.

1) Design an investigation.

Students should “formulate the statistics question” based around a particular topic. (Examples of such questions are shown in the next section.) Then, “students should clearly identify which collection method is appropriate for their investigation.”

2) Choose the data to collect.

Students “need to decide on appropriate variables, for example, age, gender or hours spent on homework, to answer the question.”

3) Gather and represent the data.

Students should collect the corresponding data in a suitable manner and then “endeavour to find patterns or relationships in their datasets by summarising their data both numerically and graphically”.

4) Interpret the data.

Finally, students should “analyse the data by comparing distributions visually using multiple graph types”.

What are some examples of what I could write about?

Are boys or girls better at guessing the number of M&Ms in a jar?

Do I breathe faster, slower or at the same rate when I’m sleeping compared to when I’m awake?

On average, do I live further from or closer to school than the other students in my maths class?

Do significantly more Irish people watch the World Cup if Ireland have qualified? 

Important: We strongly discourage students from using any of the examples above and instead recommend creating their own statistical investigation based on their own interests!

What format do I write my CBA in?

It can “be presented in a wide range of formats.”, including a written report, a poster etc.

On the next page, we provide a FREE template for those students who wish to present their CBA in the form of a written report.

What possible grades can I receive?

There are four different levels of achievement.

1) Exceptional

2) Above expectations

3) In line with expectations

4) Yet to meet expectations

How is my grade determined?

This is determined by how well you do in each section of the problem-solving cycle discussed earlier.

This is outlined in detail below.

Section Features of Quality

Define an investigation

  • Exceptional: "Poses a question that anticipates variability and seeks generalization, study design will produce as far as practical reliable and valid results by taking into account variability and confounding variables"
  • Above expectations: "Poses a question that anticipates variability and seeks generalisation; data collection plan shows awareness of how variability affects the validity and reliability of the findings"
  • In line with expectations: "Poses a question that anticipates variability and plans to collect/source the type of data appropriate for the question posed"
  • Yet to meet expectations: "Uses given statistics question and collection method"

Choose the data to collect

  • Exceptional: "Describes relationship between the variables and describes considerations related to reliability and fairness"
  • Above expectations: "Chosen measuring strategy will provide valid and reliable data"
  • In line with expectations: "Identifies variables and develops a measuring strategy for measuring the dependent and independent variable"
  • Yet to meet expectations: "Gathers and displays data"

Gather and represent the data

  • Exceptional: "Use distributions to analyse the data and justifies measures of centre used to describe the data"
  • Above expectations: "Uses appropriate data displays and describes the data in terms of measures of centre and spread"
  • In line with expectations: "Displays data in a way that allows patterns to be identified, identifies patterns and describes the data in terms of those patterns "
  • Yet to meet expectations: "Makes statements about the data displayed"

Interpret the data

  • Exceptional: "Interprets the data in relation to the original question; conclusion displays understanding of the limitations of generalising to the population and considers the need to reformulate the original question in light of the findings"
  • Above expectations: "Reports the findings and the conclusion refers to the original question and attempts to look beyond the data"
  • In line with expectations: "Makes a concrete connection to the original question of the investigation but does not look beyond the data"
  • Yet to meet expectations: "No concrete connection back to the original question"
Do I have to type up my report?

As with CBA 1, this is not necessary.

However, in regards to visualising your data, “Ideally students should also be familiar with appropriate use of technology to sort and display data.”

Who grades my CBA?

Both CBA 1 & CBA 2 are graded by your teacher.

The assessment task (AT), on the other hand, will be graded by the State Examinations Commission (SEC), the same body that grades your final examination!

Are there any other important things that I should know?


Here are a collection of other points from the official guidelines that we feel are important to consider.

“[The CBAs] are assessed at a Common Level.”

“It is encouraged, but not required, that students collaborate with classmates…”

“Each student must contribute to the work of the group.”

“Students should clearly identify which collection method is appropriate for their investigation.”

“Students should display an awareness of the importance of avoiding bias…”

“Multiple approaches can be taken to displaying and describing data…”

“[Students] may use a variety of graphical displays such as stem and leaf plots, histograms, bar charts, etc.”

“[Students] should also summarise the data collected numerically using measures of centrality and spread such as mean, median or mode and range.”

“[Students] should recognise that all findings from the analysis of samples must be interpreted with uncertainty…”

“Students must work individually to compile the report of their investigation…”

“If a typed or hand-written report is the format of their choice, the total length of a written report would typically be in the 650-800 words range (excluding reference list and research notes), but this should not be regarded as a rigid requirement.”

Do you have any sample CBA 2s?

Yes! There are three sample CBA 2s included in this section of the website.

These CBAs are for members only!