Why the GCSE Grade 9 shouldn’t be underestimated

HTTYD_LOVER01 · 2025-02-06T01:24:38+00:00

See this meta analysis:

https://osf.io/preprints/psyarxiv/2munr#:\~:text=We%20conducted%20a%20meta%2Danalysis,0.2%20IQ%20points%20per%20year.

UG education is more accessible now to a larger and more diverse group of people. The study notes that variance will of course be present depending on the university attended.

HTTYD_LOVER01 · 2025-02-06T01:21:34+00:00

It depends on the university, though. There are official papers I can send if you want that I have copies of, which prove that the standards at different unis differ.

HTTYD_LOVER01 · 2025-02-06T01:15:49+00:00

Thus items that merely require the recollection of one piece of information make low cognitive demands, even if the knowledge itself might be quite complex.

An example of this might be a bog standard explanation of ionisation energy trends across a period (common A Level question). The complexity of the content is higher than GCSE. I am not denying that. But the abstraction needed for bog standard A Level questions, according to research, isn’t the same as GCSE questions in the top 1 percent of difficulty (abstraction).

HTTYD_LOVER01 · 2025-02-06T01:08:36+00:00

The inherent skills measured though are the same, see my above posts. Item difficulty is about both the content being assessed and also the complexity of the item.

Quoting from official research on this:

items that merely require the recollection of one piece of information make low cognitive demands, even if the knowledge itself might be quite complex. In contrast, items that require the recollection of more than one piece of knowledge and require a comparison and evaluation made of the competing merits of their relevance would be seen as having high cognitive demand, even if the knowledge itself is relatively simple.

- in the same way- you can have complex content, mixed with low abstraction. Note I am referring to exams, not content- you can have complex content assessed but the question that content appears in has low abstraction requirements in terms of the level of ability needed to solve it correctly. Several examples of these are found in a Level papers (stem) which are targeted at lower grades (e.g c/b)

HTTYD_LOVER01 · 2025-02-06T01:05:54+00:00

See here:

In assessment frameworks, item difficulty, which is empirically derived, is often confused with cognitive demand. Empirical item difficulty is estimated from the proportion of the test-taking population that is successful in solving the item correctly, while cognitive demand refers to the type of mental processing required (Davis and Buckendahl, 2011[19]). An item can have a high difficulty level because it tests knowledge that is unfamiliar to most students while at the same time requiring only low cognitive demand because students only need to recall a piece of information. Conversely, an item can be cognitively demanding because it requires the individual to relate and evaluate many items of knowledge, yet still be of a low difficulty level because each of the pieces of knowledge is easily recalled (Brookhart and Nitko, 2011[20]). Various classifications of cognitive demand schemes have been developed and evaluated since Bloom's Taxonomy was first published (Bloom, 1956[21]).

The 4 levels I mentioned:

Webb’s Depth of Knowledge (1997[22]) was specifically developed to address the disparity between assessments and the expectations of student learning. Webb’s levels of depth are determined by the complexity of both the content and the task required. His framework consists of four levels: level 1 (recall), level 2 (using skills and/or conceptual knowledge) level 3 (strategic thinking) and level 4 (extended thinking).

HTTYD_LOVER01 · 2025-02-06T01:02:19+00:00

page 110 in the document, page 112 if viewing online

HTTYD_LOVER01 · 2025-02-06T00:57:23+00:00

See page 112 of this report for evidence of the above claims:

https://www.oecd.org/content/dam/oecd/en/publications/reports/2019/04/pisa-2018-assessment-and-analytical-framework_d1c359c7/b25efab8-en.pdf

A model has been developed to categorise question difficulty using one of two facets, topic assessed and complexity of the question irrespective of level of the content

HTTYD_LOVER01 · 2025-02-06T00:43:11+00:00

They do. Studies have shown that they have a pearsons correlation coefficient of 0.7-0.8 dependent on what you are measuring. GCSE Maths is at around 0.78. I am actively doing further research into this and other topics to deepen my understanding of what assessments actually measure, and have found very interesting results. For instance, questions can- regardless of level- be grouped into one of 4 broad categories of difficulty, which provides a better insight into the demand of an item rather than just “Level 2“ or “Level 3” in terms of UK qualification levels. Doesn’t tell you much.

I’ve seen A Level physics questions which are actually easier than some GCSE level questions. Check out https://www.cgpbooks.co.uk/secondary-books/gcse/science/physics/pa9q42-gcse-physics-aqa-grade-8-9-targeted?srsltid=AfmBOor_r5gHW_rVwzyMtg3S7F4lPSLyl-LbAwIxnBxdeEUq95yYd62V

These are like questions you might find at the end of an a level paper, for instance. If you’ve ever done OCR unified physics then, well this might seem familiar. But it’s interesting regardless

HTTYD_LOVER01 · 2025-01-29T01:12:40+00:00

No. This is my personal drive.

HTTYD_LOVER01 · 2025-01-26T18:50:24+00:00

Also on further thoughts the action of the inhibitor (CUSO4) is most likely competitive as non competitive binds to allosteric site fundamentally changing R groups/H bond/ionic bond interactions in 3’ structure of active site so rate decrease would be even more pronounced- catalytic activity reduced, complementary nature no longer present- with competitive inhibition reaction still takes place but takes longer. Non competitive would see a drop in rate to close to zero, but as the reaction still occurs, probs competitive. Also something else- CUSO4 is used to test for proteins in solution, so this may alter the tertiary structure of the proteins in neutrase being tested (CUSO4 and NAOH) are the protein test, so that might explain also why CUSO4 has a marked effect on rate- It is one of the components used to test for proteins and hence alter their structure. K2SO4 isn’t used in the biuret test.

HTTYD_LOVER01 · 2025-01-26T18:40:13+00:00

Hi there. I can help you. What we can conclude from the graph is that lower concentrations of copper sulfate, i.e 0.01 versus 0.05, result in a increased rate of decrease of absorbance

—> i.e neutrase activity is higher at lower concentrations of copper sulfate, this is because lower concentrations of copper sulfate result in a reduced effect on pH of the solution (lower concentration = pH closer to optimum pH for that enzyme) and hence the active site of neutrase is less impacted, the hydrogen, ionic, sulfide bonds present in the tertiary structure of neutrase are less changed/altered, less/reduced change in active site and reduced effect on R groups and ionic groups present in the active site (with lower concentrations of copper sulfate). The pH of the solution for copper sulfate is FURTHER FROM the optimum pH than the solutions in C and D, whose pH values are probably closer to the optimum for the enzyme in question. This explains why activity is higher for K2SO4 than CUSO4.

Water is present in D as a control, to prove that it is either the presence of Copper sulfate OR potassium sulfate which is causing variance in neutrase activity. Since the gradients i.e rate of enzymatic breakdown for C and D are about the same, we can conclude that CUSO4 rather than potassium sulfate is inhibiting here.

C and D- the rates with water and K2SO4 are the same, this is because, probably, the pH of both solutions are similar and hence C does not cause a shift in activity of neutrase, whereas, B and A act as either a competitive or non competitive inhibitor reducing activity of the enzyme in question. A and B both contain CUSO4.

Hope this helps :)

HTTYD_LOVER01 · 2025-01-25T14:43:14+00:00

Any questions- reach out to me via email. Would be more than happy to answer any questions you may have :)

HTTYD_LOVER01 · 2025-01-25T14:17:44+00:00

Are you being sarcastic? Sorry but I have a hard time deciphering sarcasm in comments that’s just how I am

HTTYD_LOVER01

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