GCSE SCIENCE B. SCB4P Report on the Examination June Version: 1.0

Transcription

1 GCSE SCIENCE B SCB4P Report on the Examination 4500 June 2013 Version: 1.0

2 Further copies of this Report are available from aqa.org.uk Copyright 2013 AQA and its licensors. All rights reserved. AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party even for internal use within the school / college.

3 General comments Most work was well presented helping the process of moderation. A number of schools / colleges used plastic wallets that slowed down the moderation process. Some schools / colleges used the AQA tick sheets which helped the moderation process although there were instances of the tick sheet, annotation and mark awarded not matching. Very occasionally, schools / colleges did not mark in red as requested on the generic marking grid. Lack of annotation was sometimes a problem. Some schools / colleges gave only a total mark for each strand which made it very difficult for the moderator to see how the marks had been awarded. The best examples saw the school / college using the AQA tick sheet and then annotating next to where the evidence could be found using the codes from the generic mark grid. The very best examples saw teachers giving a brief explanation too, particularly if a point was not awarded for example too much guidance had been given. There were some examples of best practice where schools / colleges had clearly internally standardised which was evident in marking of. the students work. Unfortunately there were some examples where teachers were applying marking criteria differently. More internal standardisation would have given teachers the opportunity to discuss issues and apply the criteria in the same way. A good proportion of the schools / colleges completed the insulation investigation and used good vocational contexts to help students respond. There were a number of schools / colleges who did not follow the guidance on the level of control required for each strand. Some schools / colleges gave too much guidance which hindered higher achieving students. Examples of too much guidance included giving student s resources to use in strand 1 (where students were not given the opportunity to choose helpful ones from less helpful ones), giving the hazards in strand 3, and giving templates for results tables in strand 4 and generally providing too many guiding questions for other strands. There were a number of instances where the same or very similar work had been credited suggesting that either too much guidance was given or students were allowed to work together. Students can work as a pair or group for carrying out the experiment however should have written up their entire investigation including their results table independently. Schools / colleges can read the AQA Science Controlled Assessment leaflet for more information. 3 of 7

4 Strand 1 A considerable number of schools / colleges awarded marks in this strand where students had not given their sources. These should be detailed enough for the moderator to be able to verify, for example a named text book or a specific webpage. Students had done a lot of research but had often not applied this to the investigation. For example, students had gathered a lot of information about insulation, convection, conduction and radiation, particularly in the home yet had not linked this research to the scenario of finding the best material to make a cup from for a cafe owner. Where students had successfully completed this strand, they performed well at level 1 and 2. At level 3, 1.3b was completed well but students struggled to use sufficient scientific explanation to gain credit for 1.3a. Strand 2 Students generally performed well at level 1. They were able to write a simple plan and had a vague idea of the variables involved. Some students found it difficult to include sufficient detail in their plans to allow another person to follow it. They should have included for example quantities or volumes, how to take measurements and how frequently. The plan should preferably have been in the future tense since it was an intent to carry out which is a particular requirement at level 3. The best schools / colleges encouraged the writing of predictions for the investigation that allowed students to easily link the variables. Most were credited at level 2 for describing a relationship for example, a polystyrene cup will insulate the hot water better than a paper cup. Unfortunately, students were often incorrectly credited at level 3 for a statement such as this. The student was required to give a quantitative relationship at level 3, for example If the concentration of fertiliser is doubled, the growth of the grass should double too. Strand 3 The best responses included risk assessment tables with headings such as hazard, risk, control measures and emergency action. The vast majority of students achieved level 2 in this strand for including most of the hazards and risks and describing some control measures based on common sense. Unfortunately, some schools / colleges credited risks categorised as high, medium or low without any description to say what the actual danger was. For example, hot water would have been a hazard and the risk of burns or scalds if it was spilled would have been the risk. Occasionally level 2 marks were awarded for most hazards yet some of the major risks within the investigation had not been included. At level 3, students should have used scientific reasoning to explain how to reduce risks. Strand 4 Students are required to construct their own tables in order to achieve 4.1b, 4.2b and 4.3b. Where schools / colleges wanted to allow students to pool their data, they should have been given the opportunity to construct their own tables first and then given a template after where students could record data and identify their own within it. A number of schools / colleges awarded 4.2a and 4.3a where students had not repeated their experiment. It was difficult to agree these marks since without repeats; it was very difficult to assess reliability. To award 4.2b and 4.3b, students needed to ensure they used consistent 4 of 7

5 decimal places which were appropriate and at level 3, correct headings and units included in the table that made it clear what the data was. If students repeated their results, they were awarded 4.2c. Occasionally, students had been awarded 4.2c without repeats. Repeats should have been of the same measurement for example, taking the temperature of water cooling in a paper cup two or three times over rather than once with a paper cup and once with a polystyrene cup. Students can gain credit for 4.2c if they explained why they thought it was inappropriate to repeat their experiment however a lack of time was not credited. Occasionally, schools / colleges awarded 4.3c for students identifying anomalies without the additional explanation of why it was appropriate to repeat. Strand 5 Students generally performed well at level 1 however it was impossible for some students to be awarded marks for calculating means if they had not repeated the experiment. Some schools / colleges awarded 5.1b and 5.2b for simple calculations such as temperature changes or a mean of just two results. The marking guidance states that the mean should be of three results. Some students were awarded 5.2a and even 5.3a without reference the quantitative relationship. They needed to have used the data collecting in the experiment to discuss the patterns for example The polystyrene cup was the better insulator because it only lost 20 C where the paper cup lost 35 C in 10 minutes. At level 3, students needed to have described the quantitative nature of the relationship and corroborated this with data. Few students carried out level 3 calculations but when they did, they needed to record their answers with appropriate significant figures and include units where appropriate. Most students managed to plot a bar chart although some were disadvantaged by the lack of teacher annotation. If there is no annotation, the moderator had to assume level 1. At level 2, the student was expected to have plotted the points correctly and included axis labels and units. At level 3, if it had been appropriate to draw a line graph with a line of best fit, this had been expected over a bar chart. Strand 6 In a similar way to strand 5, students were expected to use data when concluding their findings. Most students that attempted strand 6 successfully made some comparison to secondary data although this was mostly to other class data rather than the secondary data provided in the Candidates Notes. Students struggled to successfully complete 6.2bii. A number of students explained why their results were not valid rather than how to improve the validity. Repeats would not have improved the validity though since a systematic error would have repeated the same error. Students should have mentioned for example more comparison to other class data or secondary data. Few students attempted level 3. Where they did, they did not always discuss their conclusions in sufficient detail or make reference to the limitations in the data. Scientific understanding was often too brief and did not illustrate a comprehensive understanding. Teachers did not always take the assessment of the Quality of Written Communication into account in this strand and awarded high marks for illogical or brief conclusions. 5 of 7

6 In both strand 5 and 6, very occasionally, teachers awarded marks for incorrect conclusions where the patterns described did not match the results included in the students work. Strand 7 Most students achieved at least level 1 and 7.2ii. Some students were incorrectly awarded 7.2i for describing how well their experiment went rather than commenting on the effectiveness of the working methods i.e. how good the chosen method was. Students were often awarded 7.2ii for suggesting repeats, as described above; repeats would not necessarily have made a suitable improvement and were therefore not credited. Students would have gained credit though for suggesting improvements to the working methods. This would have been easier if they had evaluated the working methods for 7.2i. In a similar way to strand 6, students were often awarded marks at level 3 for brief work that was not clearly expressed. The best examples saw students writing in prose and giving a detailed account of the strengths and weaknesses. 7.3ii required students to give fully justified suggestions to allow them to collect more reliable and valid evidence. The Quality of Written Communication was also assessed in this strand and even if the teacher had credited all points within a level, if the student had not written a clear evaluation with few spelling, punctuation or grammar errors, they could not gain full credit. It is recommended that a school / college regularly refreshes their practice by using the Standardisation Opportunities offered by AQA. 6 of 7

7 Mark Ranges and Award of Grades Grade boundaries and cumulative percentage grades are available on the Results Statistics page of the AQA Website. Converting Marks into UMS marks Convert raw marks into Uniform Mark Scale (UMS) marks by using the link below. UMS conversion calculator: 7 of 7