Biology

This video looks at how the general assessment principles are applied in A-level Biology. It looks at assessment objectives, different question types, and gives an insight into our question paper development process. It also looks at the different types of mark scheme and demonstrates how questions can be developed for use in the classroom.

Transcript

Hello, I am John Greenhalgh, I am a Lead Examiner for A-level Biology, and today I am going to be talking to you about assessment principles in A-level Biology papers. Hopefully you'll have already seen our what makes good assessment videos about the principles of assessment, which cover concepts such as validity and reliability and what those terms mean. In this video, I'm going to talk about how those principles apply in biology.

The objectives of today’s presentation are:

• To understand how A-level Biology exam papers are produced.
• To look at how different types of questions cover the assessment objectives.
• To look at mark schemes and how they are developed.
• To see how you can use this information to develop your own assessment materials.

Exam structure.

There are three assessment objectives in A-level Biology.  AO1 is to demonstrate knowledge and understanding.  This is recall of the taught specification and can be subdivided into ideas, or processes, techniques and procedures, i.e., experimental or practical work.  AO2 is applying knowledge and understanding.  Again, this can be subdivided into ideas, or processes, techniques and procedures. Each of these can be further subdivided into theoretical or practical contexts, and qualitative or quantitative questions. Most maths questions on the exam papers are AO2. AO3 is analysing, interpreting and evaluating.  With this, subdivisions include whether students need to make a judgement or reach a conclusion, or develop or refine a practical procedure. These subdivisions of each assessment objective can be found on the assessment objective grid that we will cover shortly.

This table shows the approximate weightings on each paper of the assessment objectives.  You will be able to see that these weightings are not equal on each paper, and this is something you may wish to consider if you are designing your own assessments for end of unit tests or mock examinations by combining questions from different papers.  To make your assessments fair and representative of actual papers, the balance of assessment objectives should fall within these ranges.

Now we’ve discussed assessment objectives, it’s time for a quick ‘know your assessment objectives’ activity.  See if you can apply your knowledge of the assessment objectives to guess which objective is being tested in each of the following questions. Here is your first question. Identify which assessment objective, so that’s AO1, AO2 or AO3 is being tested in the two questions visible on screen now.

You were correct if you suggested that question 1.1 is assessing AO1, and question 1.2 is assessing AO2.  There are some additional important things to note about these questions.  Firstly, the command words are clear in each question; describe for 01.1, and explain for 01.2.  The materials including chromatography paper and a ruler and pencil etc are given as a list with each material on a new line.  If this had been written with each in a sentence separated by a comma, this may not be accessible to all students. The number of marks is indicated underneath each question, this can help clue students into how much they are expected to write. The number of answer lines is always appropriate for the question, this also gives an indication to students of how much they need to write.  The general rule in A-level Biology is three lines per mark point, unless the answer is just one word.  These lines can also be prefixed with numbers or words to help guide students in their responses.

You may notice that question 01.1 is an example of a less demanding structured question.  These are often used at the beginning of an exam paper. As you may know, paper 1 has 15 marks of structured AO1 questions at the end, and paper 3 has the 25-mark essay at the end but, generally, more demanding structured question appear later in the paper. The demand should also increase within each question as demonstrated here, as 01.2 is increasingly difficult when compared to 01.1. Again, please consider which assessment objective is being tested here?

This is an AO2 question that demonstrates an example of both practical skills and maths skills tested in one, as it relates to an experiment and is asking students to calculate. This question also provides additional instruction to students by asking for the answer in dm3 and in standard form, which they must obey to score full marks. And now, which assessment objective is being tested in this question? It’s worth noting that in order to fit the question to the slide, I have removed the table which accompanied this question.

This is an AO3 question. The stem of some AO3 questions can be up to one page in length, providing detail and result of an investigation.  If a stem is this long, it is normally followed by a question or questions that make up several marks, and not just one or two marks in total. Results in questions can be provided in a variety of formats, but often this is in the form of a table or graph. AO3 questions are usually 3 to 5 marks in length. Now for our final assessment objective question where, again, for space saving purposes I’ve just included the first 5 lines of a passage – which objective does question 10.1 intend to assess?

You may have noticed that the rubric underneath the passage states that students need to use their own knowledge and the details provided in the passage, and this is the case with 10.1 which assesses AO1 and AO2.  If students do not use their own knowledge, AO1, and information in the passage, AO2, they will not be able to access all four marks.

Following on from considering assessment objectives, we should look at the structure of the three A-level Biology papers.  In biology, there is no practical paper as there is within A-level Chemistry or Physics. Instead, practical skills are assessed in all three papers.  Each paper must contain a minimum of 15% of questions that test practical skills. The practical skills are outlined in section 8.3 of the specification and are assessed in a wide variety of ways and are not solely based on the 12 required practical activities. Additionally, each of the three papers must contain a minimum of 10% maths with a minimum standard of higher tier GCSE Maths.  The maths requirements and exemplifications can be found in section 6 of the specification.  It is worth noting that only questions that involve calculations are classified as maths. So, for example, describing and explaining data from a table or graph, or selecting and justifying a statistical test a scientist might have used, is not considered a maths question.

On top of the practical and maths requirement of each paper, paper 1 assesses only the first four topics of the specification in two broad sections.  The first 76 marks are a mixture of long and short questions. The last question is worth 15 marks in total, and this is made up of AO1 extended response parts normally ranging from 4-6 marks each.

Paper 2 assesses only the last four topics of the specification in two broad sections.  The first 76 marks are a mixture of long and short questions.  The last question is worth 15 marks in total and is a comprehension question.  The writing of the comprehension is quite a skill in itself.  To make it a true comprehension, every question that follows must only be answerable as a result of the student having read and understood the passage in the stem of the question, and to be accessible, that passage must contain clear information, with nothing extraneous that the student does not need to read in order to answer the question parts.

Paper 3 is a synoptic paper and can assess any of the eight topics of the specification in three broad sections.  The first 38 marks are a mixture of long and short questions.  The penultimate question is worth 15 marks in total and includes a critical analysis of experimental data, and the final question is a 25-mark essay, in which students write one essay from a choice of two titles. I will discuss the essay in detail later in this presentation, but for now, it is worth noting that the essay contains 13 marks of AO1 and 12 marks of AO2.  What this means for paper 3, is that the rest of the paper will have a higher proportion of AO3 questions when compared with paper 1 and paper 2.

Within all of the biology papers, none of the questions is aimed at any grade, for example no question is specifically aimed at A grade students, or E grade students.  Papers do generally start with more AO1 and AO2 questions, and question complexity and difficulty should increase throughout each question and across the paper, with the exception of the last question on paper 1 made up of AO1 extended response questions and the last question on paper 3 which is the essay.

In biology, there are certain command words that are used regularly. These include ‘describe’, ‘compare’ and ‘name’ which are commonly used to assess AO1.  The command words ‘explain’ and ‘suggest ‘are commonly used to assess AO2 and the command word ‘evaluate’ is commonly used to assess AO3. The full list of command words and their meanings in biology can be found on AQA’s website. Misinterpretation of these command words can result in low marks, for example, a student explaining when they have been asked to describe or vice-versa.  As a step on from GCSE biology, two command words can be used in one question in A-level biology, for example describe and explain, or suggest and explain.  When writing questions there are occasions when examiners will write a clear command to not include content, like this example from paper 1, 2023 on screen now.  Examiners do this to help students accurately focus their answer.

The Lead Assessment Writer has to follow a blueprint document that details the required structure of each paper including what it can assess, the types of questions and assessment objective balance required.  Once the first draft of the paper and mark scheme is completed, an assessment objective grid is put together. The template grid for paper 3 can be seen on the screen now.  Every section of this grid must be completed for each paper to ensure Ofqual requirements are fulfilled, and that the assessment objective balance for each paper is correct and in line with that indicated in the specification.  This gird is updated as revisions are made to the paper during the paper production process and is used by AQA to ensure consistency from year to year and to monitor coverage of specification.  There are some key features of the assessment objective grid:

Each question part must have a specification reference; this allows us to track specification coverage over time and to ensure that every question is firmly rooted in the specification content. Maths marks can be allocated to question parts - remember this needs to be 10% of the total marks available. Practical marks are also added to the grid - these need to be 15% of the total marks available. We then have each of the assessment objectives AO1, 2 and 3 and the subdivisions highlighted earlier.  As marks are entered, they are totaled up at the bottom, and these need to fall withing the mark ranges stated for each assessment objective.    Hopefully you will appreciate that writing questions and exam papers is a very involved, specialist process with many stages of checking and revision.  Indeed, throughout the process some questions that make it onto live papers have changed to the point of being unrecognisable from their first draft versions and some questions from that first draft will never make it onto live papers, as they may be deemed inaccessible, or not valid to use.  That said, you may wish to write your own exam questions for your students, and to help you, here are ten tips from AQA’s biology lead assessment writers.

1. Firstly, begin with the mark scheme.  What response are you wanting from students?  From this you can then determine the mark tariff for that question, and which assessment objective it will test.
2. Check that your question assesses content from the specification.  Even experienced lead assessment writers will check their questions against the coverage and wording from the specification.
3. Use the ‘active voice’ in questions, not the passive voice.   The active voice can be seen to be used in the stem to this question from paper 3, summer 2019.  If the passive voice was used, this question would start with ‘The effect of caffeine on heart rate in human volunteers was investigated by a research scientist.  The volunteers were divided in to three groups by the scientist.  The same volume of fluid was given to each group’, and so on.  If you are writing your own questions then it will help your students most if you follow the question rubric they’re most used to.
4. The language you use needs to be accessible.  Use the simplest wording possible.  If a novel word is being used, for example the name of a chemical, drug or gene, or a novel context is being used, for example, a disease or process, this should be introduced and explained as early as possible in the stem of the question. This can be seen in the example on screen with question 06.1 from paper 2 summer 2021.  This shows novel contexts being introduced early in a question on which all parts of the question are based. This also shows the use of abbreviations in the question once the full name of the disorder and treatment have been given.
5. Long sentences should be split up.  Should a long sentence be required, the command word should not be at the start of the sentence, instead it should be separated at the end and placed on a new line.  This can be seen in the example on screen with question 03.2 from paper 3, summer 2022.  ‘Explain why’ could have been added at the start of the question, but to make the command clearer, and so it is not forgotten or lost, it is placed after the question.
6. When detailing processes, techniques and procedures in the stem of a question, it is a good idea to use bullet points or numbering to increase accessibility. This can be seen in question 03.4 from paper 3 summer 2019 where three bullet points have been used in an example that we previously looked at.
7. Any tables and graphs added to questions need to be in the requisite standard as exemplified on previous AQA exam papers.
8. There should be no overlap within, or between, questions.  That is, questions should not give away the answers to other questions on the paper and there should not be any identical mark points on different questions in the same paper.
9. Questions should be designed so that they differentiate between students. Question complexity and difficulty should increase throughout each question and across the paper.
10. Data and resources used, including novel contexts for AO2 and AO3 questions in live papers, are real and almost entirely taken from published scientific journals with copyright implications.  AQA do apply for permission to use this and sometimes permission to alter data to make it more accessible to students.

Mark schemes.

It is also important when considering assessment, to consider the mark scheme as well as the question. Mark schemes are discussed in depth at every stage of the exam paper production process, however, they’re not finalised until many student responses are seen and analysed in respect of the mark scheme during the standardisation process. This is important so that a finalised mark scheme can be applied fairly and consistently to award marks across the entire range.  The mark scheme should contain the simplest acceptable A-level wording.  Student responses that are more detailed or use more complex language but are still equivalent to the mark points are, of course, acceptable.  On the biology papers, aside from the mark scheme for the 25-mark essay question, all other questions are examined using a points-based mark scheme.  This is a mark scheme with a series of independent mark points that, if reflected in a student’s response, lead to the allocation of marks.  Here is an example of a points-based mark scheme from the summer 2023 paper 2 and there are some key features to note:

1. Firstly, where there are multiple mark points, each mark point is numbered and separated by a semicolon.
2. If words are in brackets, they are not required in a student’s response, and are normally the context for that mark point.  That said, if the context is wrong, this can disqualify a student from scoring that mark point.  If a word is underlined, this must be in the student’s response.
3. The mark tariff also states the assessment objective that is being tested.
4. The comments section is very important and must be applied.  What is in this section is often added in light of what is seen in student responses.  As a general rule, what is in the comments box does not need to be taught to students.
5. If examiners are ordered to accept an answer in the context of, this means there is an equally acceptable alternative to the mark point it relates to.
6. Ignore means exactly that, examiners should treat relatable content as if it is not even there.
7. Reject means that if a student states this, they are disqualified from this mark point, even if the correct answer for that mark point is also present.

Mark scheme writing advice.

An effective assessment is very much dependent on a well-developed mark scheme.  To help you write your own points-based mark schemes, here are a top ten tips from biology lead assessment writers. First, apart from the essay, use points-based mark schemes as previously outlined.  Ensure you continually refer to the specification to ensure what you are testing is valid.  Use current mark schemes as a reference for the instructions as the start, the style used, and to check the correct use of terminology and detail required. If the command word is ‘explain’, ensure that the number of available marks match the mark tariff. Ensure alternatives for same mark points are actually equivalent, and ensure all alternative calculating methods and routes to the same answer are included in Maths questions.  It is also important to consider as many ways as possible to award less than full marks for incorrect final answers in maths questions. This can be seen in the example here with question 02.2 from paper 3, summer 2023.

Contexts can be bracketed if they are not essential in a student’s response, but remember an incorrect or contradictory context may disqualify that mark point. This can be seen in question 04.1 from paper 3, summer 2023.  The contexts of the vesicle and SCFR were bracketed, but students often failed to read the context of the question and referred to ‘a phagosome fuses with a lysosome, and lysozyme hydrolyses the cell.’  Whilst this is almost word for word mark points one and two, the contexts are wrong for both mark points.

Use the comments box to provide guidance on what to accept, ignore or reject.  This can also be used to add alternative responses that students often write, but do not need to be taught. Underline words that must be in a student’s response.  A word of caution, only use this if absolutely necessary.  For example, in the mark scheme for question 01.4 from paper 1 summer 2019 it is better to embolden the words ‘due to’ to highlight the requirement for these words rather than underline, as alterative equivalents such as ‘as a result of’ or ‘owing to’ would be acceptable.

If the specification has abbreviated a term such as GP within Photosynthesis, then this can be reflected in the mark scheme too.   If students choose to use specification abbreviations in their answers, then this is of course entirely valid.  One term relating to photosynthesis that is not abbreviated in the specification is ‘triose phosphate’, so if a student refers to ‘TP’ alone without first writing the full term and then adding ‘TP’ in brackets afterwards, they would not be awarded relevant marks in an answer.

The use of a principle mark to provide credit for a response which shows understanding but lacks detail. This can be seen highlighted on this example of question 06.4 from the summer 2023 paper 3 which has the principle mark of ‘If no other marks awarded, accept 1 principle mark for the idea that if SD overlap there is no significant difference or the converse’

We cannot get through a presentation without mentioning the essay question and accompanying mark scheme! As you will know, the paper 3 exam requires students to write a 25-mark essay, and this is to test their ability to bring together principles from at least four different areas from the A-level biology specification.  It is an exercise in synopsis, not an excuse to for students to tell examiners everything they know about just one or two topics; indeed, students that do this will not gain high marks.  As can be seen on the screen there is a choice from two essay titles, both will allow the freedom to respond in a variety of ways and students can pick the one that bests fits their knowledge of biology to show what they know.  Examiners will be looking for evidence of knowledge and understanding in keeping with an A-level course of study, selection of material relevant to the title and drawn from different areas of the course, and the ability to present an argument coherently and logically, using appropriate biological language. The essay is allocated as 13 marks of AO1, and 12 marks of AO2.  Therefore, the essay is not a list of facts learnt over two years.  The essay is themed, with the theme normally being ‘the importance of.’  Addressing this theme is roughly worth 12 out of the 25 marks, and so must be addressed at the correct level.  Paper 3 is designed to allow 45 minutes for student to write the essay.  Examiners understand that students are under pressure in an exam, and therefore do not expect perfection.  For a more in-depth look into essay response, please refer to the AQA teaching guide on the website.

On screen now is a section of the level-based mark scheme used for the 25-mark essay question. Three of the five levels can be seen. Students’ essays are read, annotated and each essay is matched to the level that best fits the quality of material presented.  It is important to note that the statements must be adhered to and are applied as a ‘best fit’. A mark within that level can then be determined based on these statements. The levels mark scheme is proceeded by a commentary on terms and statements used in the mark scheme, as some of the words and statements used are open to different interpretations.  This commentary defines the meanings of these words and statements in the context of marking the essay.  These are important to note for marking and must be read and understood.  For example, a significant error being defined as one which significantly detracts from the biological accuracy or correctness of a described example.

Thanks for watching, I hope you found this presentation informative and useful. If you have any questions or feedback, then please do email biology@aqa.org.uk.

Questions you may want to think about

• How can you use these insights to prepare your learners for exams?
• Do your internal assessments reflect the approach of the exam? To what extent do you want them to?
• What’s the most important or surprising thing that you’ve learned? How might it influence your teaching?