English Marking

partyatmygaff

I've always wondered about the way English is marked at HL. An essay that gets a C from one teacher might get an A if it were marked by another teacher and that's what really makes your result so unpredictable (Well in my opinion anyway).

So i've decided to try something out here just to see how variable the marking in English is. I was thinking something along the lines of posting up the introduction of an essay you wrote for your Shakespearean play (In my case Hamlet) and then everyone else can make an attempt at estimating what grade it deserved. Then after a few attempts have been made the person can reveal the actual grade they received.

Ok so i'll get the ball rolling so to speak, here is the intro to an essay regarding why Claudius is such a great villain.

It is without a doubt clear to see that Claudius is the villainous, treacherous antagonist in the play. He is selfish and cruel, deceitful and manipulative yet sly and crafty. He rarely acts with a conscience and even at that there is an ever present vested interest. His treachery is the cause of death for almost all of the play's characters, including his own. Even his opening lines in the play are deceitful as he pretends to mourn the death of the brother he killed for none other than his own selfish ambition. His words reflect his twin sided appearance as he describes "One auspcious and one dropping eye". His words reflect his twin sided outward appearance as he describes "One auspcious and one dropping eye". Yet the man does display some human conscience but in no way does it offset the severity of his villainous actions. Particularly as he continues to pursue the killing of Prince Hamlet despite his private pleas for forgiveness. His facade of being a loving husband to Gertrude and a caring step father to Hamlet is ironic in that it is believed by all but Hamlet, similarily to how Hamlet's feigned madness is believed by all but Claudius..

So how would you rate it? Give a proper grade as in D3-A1 not just "Yep I think that's X grade".

Anyone else willing to give it a shot?

pathway33

We need the entire essay. Doesn't the marking work on P L C something. Like 20 30 20 30 or something? It was well described in a thread only last week I think. Regardless, we need the whole essay

partyatmygaff

I know how it's meant to be marked but let's assume you're flicking through 20 or so essays and you can only read the introduction of each. Where would you put it? If anyone else wants to put a part of their essay too, feel free.

DL Saint

It's marked on P C L M all out of 20 I think:)

partyatmygaff

I think you're all misunderstanding me. I know how the marking scheme works.

I just want to see how subjectively marked English is by seeing how much the grades vary from person to person.

pathway33

In my book an introduction is only as good as what is produced in the essay. If you have a stunning intro which promises the moon and stars by promising to analyse 10 points and then in the essay you only focus on 2 points in detail then the introduction was a lead up the garden path. Give us the essay

I've never heard of an english teacher who marks by just reading introductions and ranking them and then going back to read the entire essay. Hate to keep harping on this point but....give us the essay . Shu you won't be using it for real for another 15 months

partyatmygaff

It's 4 pages long though >_>

Surely an intro would suffice for a rough estimate of what grade it's worthy of?

pathway33

Grade B1. Deals with all main points encompassing the whole play. Unfortunately the writer got messy with the last 2 sentences. The sentence 'Particularly.......' is out of joint. The last sentence should be broken into 2. If it wasn't for this mishap the writer would have scored 89%

spurious

partyatmygaff wrote: »

I think you're all misunderstanding me. I know how the marking scheme works.

I just want to see how subjectively marked English is by seeing how much the grades vary from person to person.

Of course marks will vary. That is why when people are correcting in the summer, they have to send their supervising examiners samples of their correcting from the first 20 scripts, first 100, next 100 etc.

It's to make sure everyone is marking to the same standard.

Flecktarn

Great idea, but don't think it will work on boards:pac:

partyatmygaff

pathway33 wrote: »

Grade B1. Deals with all main points encompassing the whole play. Unfortunately the writer got messy with the last 2 sentences. The sentence 'Particularly.......' is out of joint. The last sentence should be broken into 2. If it wasn't for this mishap the writer would have scored 89%

Thank you. See? That wasn't too hard now was it? :P

spurious wrote: »

Of course marks will vary. That is why when people are correcting in the summer, they have to send their supervising examiners samples of their correcting from the first 20 scripts, first 100, next 100 etc.

It's to make sure everyone is marking to the same standard.

Well yes because it's marked subjectively. I just want to see how subjective it is.
What grade would you say it would have gotten?

DL Saint

spurious wrote: »

Of course marks will vary. That is why when people are correcting in the summer, they have to send their supervising examiners samples of their correcting from the first 20 scripts, first 100, next 100 etc.

It's to make sure everyone is marking to the same standard.

When I looked at my english script last year I found that it was marked twice and the 2nd time the chief examiner gave me extra marks,I went from a C to a B in English:D

implausible

partyatmygaff wrote: »

Surely an intro would suffice for a rough estimate of what grade it's worthy of?

No, it wouldn't! An introduction is just that, an introduction. It's impossible to mark using PCLM as there isn't enough info to ascertain whether the essay shows a clear and original purpose or follows through coherently. Language skills can't be determined from a few lines, but I will note that some of your sentences are too long and lack punctuation.

pathway33

partyatmygaff wrote: »

Thank you. See? That wasn't too hard now was it? :P

It was actually considering I was still recovering from the disappointment of not getting the essay

partyatmygaff

deemark wrote: »

No, it wouldn't! An introduction is just that, an introduction. It's impossible to mark using PCLM as there isn't enough info to ascertain whether the essay shows a clear and original purpose or follows through coherently. Language skills can't be determined from a few lines, but I will note that some of your sentences are too long and lack punctuation.

The only moderately long sentence in that entire section was

"His facade of a loving husband to Gertrude and a caring father to Hamlet is ironically believed by all but Hamlet similarily to how Hamlet's feigned madness is believed by all but Claudius."

Surely that's not too long? The rest were at most 3/4 of a line long.

spurious

partyatmygaff wrote: »

What grade would you say it would have gotten?

I'm not an English teacher, so I'm not sure how useful an exercise it would be, but if you insist I'd make the following observations:

Apart from some punctuation issues, there is a lot of unnecessarily 'unusual' words and phrases in it (see underlined sections). It does not flow as an answer.

It is without a doubt clear to see that Claudius is the villainous, treacherous antagonist in the play. He is selfish and cruel, deceitful and manipulative yet sly and crafty. He rarely acts with a conscience and even at that there is an ever present vested interest. His treachery is the cause of death for almost all of the play's characters, including his own. Even his opening lines in the play are deceitful as he pretends to mourn the death of the brother he killed for none other than his own selfish ambition. His words reflect his twin sided appearance as he describes "One auspcious and one dropping eye". Yet the man does display some human conscience but in no way does it offset the severity of his villainy. Particularly as he continues to pursue the killing of Prince Hamlet despite his private pleas for forgiveness. His facade of a loving husband to Gertrude and a caring step father to Hamlet is ironically believed by all but Hamlet similarily to how Hamlet's feigned madness is believed by all but Claudius.

That last sentence reads very oddly to me.
Mark-wise, I really wouldn't know, sorry. The problems would be (for me) more in the style of writing, rather than the points you are making, which seem valid to me, allowing it's 30 years since I answered a Leaving Cert. question on the Prince of Denmark.

partyatmygaff

His facade of being a loving husband to Gertrude and a caring step father to Hamlet is ironic in that it is believed by all but Hamlet, similarily to how Hamlet's feigned madness is believed by all but Claudius.


Ah, I think I've found out what has been making the last sentence so odd sounding. I had missed one of the commas while I was typing. (The comma was included in the actual essay by the way) I also forgot to type in the word "being" in that last section aswell. I also (somehow) made a mess of typing some of the 2nd last line. "Ironically" should read as "Ironic in that it is".

partyatmygaff

Ok well, re-reading all of that again and it looks as if I made a mess of a good bit of that essay typing it up here.
The other section which I made a total mess of when typing was

"His words reflect his twin sided outward appearance as he describes "One auspcious and one dropping eye". Yet the man does display some human conscience but in no way does it offset the severity of his villainous actions"

I've edited the original post. It is now exactly what I had written in the essay.

soccymonster

I'm in 5th year. Getting A's or high Bs in poetry and hamlet essays. But just reading that essay, i'm just wondering in the leaving cert, if i want to get the high grade do i have to have sucha wide vocab.

Like i'm reading that and i don't even understand some things he's saying (in a good way :P). I'm just kind of wary that my teacher isn't marking me right because my language is preety basic explaining points. (sorry partyatmygaff for taking your thread )

theowen

soccymonster wrote: »

I'm in 5th year. Getting A's or high Bs in poetry and hamlet essays. But just reading that essay, i'm just wondering in the leaving cert, if i want to get the high grade do i have to have sucha wide vocab.

Like i'm reading that and i don't even understand some things he's saying (in a good way :P). I'm just kind of wary that my teacher isn't marking me right because my language is preety basic explaining points. (sorry partyatmygaff for taking your thread )

Well, yes. A third of the marks are specifically for vocab after all.

partyatmygaff

soccymonster wrote: »

I'm in 5th year. Getting A's or high Bs in poetry and hamlet essays. But just reading that essay, i'm just wondering in the leaving cert, if i want to get the high grade do i have to have sucha wide vocab.

Like i'm reading that and i don't even understand some things he's saying (in a good way :P). I'm just kind of wary that my teacher isn't marking me right because my language is preety basic explaining points. (sorry partyatmygaff for taking your thread )

Hey. You're more than welcome to post some of your stuff here soccy.

Maybe we can all rate each others work? We could even steal learn a few phrases off each other's essays :pac:



Oh yeah on a side note.....

That essay actually got me 71%. But my teacher marks our papers very hard according to some 6th years that have her as a teacher. It was the highest mark in the class for that particular essay but only me and another person in my class got that grade for the essay.

So it was marked as being a B3 so I guess pathway was not too far off with his guess.

theowen

partyatmygaff wrote: »

Hey. You're more than welcome to post some of your stuff here soccy.

Maybe we can all rate each others work? We could even steal learn a few phrases off each other's essays :pac:



Oh yeah on a side note.....

That essay actually got me 71%. But my teacher marks our papers very hard according to some 6th years that have her as a teacher. It was the highest mark in the class for that particular essay but only me and another person in my class got that grade for the essay.

So it was marked as being a B3 so I guess pathway was not too far off with his guess.

It's a rather long intro', no? I've always been told a short, reworking of the question title works best.

implausible

theowen wrote: »

Well, yes. A third of the marks are specifically for vocab after all.

No, they're not. A third of the marks are for Language: paragraph structure, punctuation, lively interesting phrasing, energy, fluency and vocabulary. Knowing a few big words will not get you full marks for L.

FredBaby!

its the same in other subjects too, not just english. I regularly fail higher Irish in school but then I get my grinds teacher to correct my stuff and I get from 80 to 90 percent! I suppose it depends on how cruel your teacher is!

theowen

deemark wrote: »

No, they're not. A third of the marks are for Language: paragraph structure, punctuation, lively interesting phrasing, energy, fluency and vocabulary. Knowing a few big words will not get you full marks for L.

Tomato, tomato(doesn't really work typing:(). You do need a good vocab though.

Stewie Griffin

Hi OP, I'm an English teacher and I wouldn't be crazy about that opening paragraph. It's a little bit long and meandering - someone else suggested that you should re-work the keywords in the questions. It's not quite that simple but it's definitely not as complicated as you make it either.

Above all, your opening paragraph should be aiming to encourage the examiner to read on. Be dramatic if you have to, but make them want to read on.

On a more general level, I partially take your point about English marking being somewhat subjective. That would be true to a certain extent on Paper 1, but it isn't true for Paper 2.

The marking schemes are available on-line and they will confirm this.

Finally, to answer your question: you show a good depth of knowledge of Claudius so that is definitely in your favour. In so far as a judgement can be made on just one paragraph, I would give it a B3 or so.

partyatmygaff

Ok since everyone is asking me to type up a full essay so as to be able to judge it better i've decided to type up one of my shorter poetry essays (1 3/4 A4)

The question was

" Describe the main themes of the poetry of Patrick Kavanagh" and we were asked to mention about 2-3 poems.

My essay

Patrick Kavanagh: from biterness and desire to joy and fulfillment

There is a very noticeable difference in the overall theme, tone and imagery between Kavanagh's early poems and the poems that he composed following his operation in 1955. I believe that his ailment and his almost miraculous recovery which gave him a new lease of life had given him a new appreciation of life. The fruits of this change in his world view is very prominent in his later poetry such as "Lines Written on a Seat on the Grand Canal in Dublin"

In "Advent", a poem he composed prior to his 1955 operation he shows an intense desire to surrender knowledge so as to regain the innocence of a child whom can find wonder in the most mundane, banal and ordinary that life can offer. He attempts to re-experience the wonder and appreciate by his Advent sacrifices such as the "dry, black bread" and the "sugarless tea" inside the "advent-darkened room". He believes the Advent sacrifices will help him to rekindle the wonder and the newness of all by enjoying all that he gave up as a penance for Advent. He is somewhat bitter and resents the "Knowledge we stole but could not use". He wishes to return to innocence and rid himself of knowledge for it is knowledge which makes the wonders of life mundane.

He speaks with a far different tone in his later works such as "Lines written on a seat on the Grand Canal, Dublin". The bitterness and resentment for past events that we see in "Advent" are in complete contrast with "Lines written on a seat on the Grand Canal, Dublin". This poem gives off an aura of fulfillment, joy and hope for the future such as his wish to be commemorated with "no hero-courageous tomb - just a canal bank seat for the passer-by". His use of hyperbole shows that through his newfound appreciation of life the ordinary and plain such as a canal lock "Niagarously roars" and that that the barge is coming from "Athy and other far-flung towns mythologies". His desire for wonder in life is fulfilled as evidenced by his use of language with bright, positive connotations. It is clear to see from his poetry that his life-long dream had been fulfilled. He had made the transition from bitterness and desire to joy and fulfillment.

That is a full essay, what do you think? Grades-wise of course.

dan_d

I have to agree with Spurious. It sounds promising, but you seem to be using a lot of unnecessary words. It's hard work to understand exactly what you're trying to say, because there are a lot of adjectives - too many.

As for the short essay.....the sentence "the fruits of this change" is unnecessary. Simply "the change in his attitude" should be sufficient.Insert a comma in the following "1955 operation, he"...it's a long sentence.The words "mundane, banal and ordinary " are repeating the same sentiment. Choose one of them to use, at most, 2. " the poem has an aura of fullfillment", rather than "the poem gives off an aura of fulfillment". Should you give an example of the language with bright,positive connotations?

Note that I'm not a teacher, but you're looking for a few pointers! At a rough guess I'd say maybe a B2 possibly? That's very rough. Your language is very good, but tone it down a bit, sometimes it's too much and it's hard to figure out exactly what your point is.
(FYI I got an A1 in LC english)
Best of luck!:)

pathway33

Grade C1: The student was asked to mention 2 or 3 poems and yet only mentions 1 poem in the introduction. The student dives into a division of the poet’s themes based on stages of life without specifically mentioning the themes. As a reader I want to know what’s coming. Name the poems and name the themes. The intro is about getting into second gear. Start simple and build it up. You saw a blank page got a rush of blood to the head and just went for it. You need to be more mechanical. Slow down!
‘Advent’ is not mentioned in the introduction.
The fruits of this change in his world view is very prominent
innocence of a child whom can find wonder
The student has an obvious wardrobe full of vocabulary but seems to be too lazy to re-read his essay. The student should re-read his essay out loud before submitting in future as it does not flow well. The student should not simply lash down every fancy word he/she knows onto the page. The student is cooking dinner for 2 but laying a table for 50.
He attempts to re-experience the wonder and appreciate by his Advent sacrifices such as the "dry, black bread" and the "sugarless tea" inside the "advent-darkened room".
One cannot ‘attempt to re-experience the appreciate’. One can either appreciate or not appreciate. One can however attempt to re-experience the appreciation. Splitting of sentence required.
This poem gives off an aura of fulfillment, joy and hope for the future such as
Replace with ‘as indicated by’
His use of hyperbole shows that through his newfound appreciation of life the ordinary
Insert comma between ‘life’ and ‘the’
and plain such as a canal lock
Insert comma between ‘plain’ and ‘such’
The student contrasted the 2 poems well. Conclusion should have a paragraph of its own. The student is the Jarno Trulli of essay writing. The student shows the potential to be an A student but this requires consistency throughout.
P.S I’m not even too sure myself about the whole ‘appreciate’ thing above. I may not have read it right. Just that it doesn’t read right. I myself am too lazy to read back over it

P.P.S apologies for all the italics. Didn't copy well from word. Laziness prevents me from fixing it. Perhaps a nice mod could

Flecktarn

That Kavanagh essay seems ridiculously short, how long was it?

pathway33

pathway33 wrote: »

Grade C1: The student was asked to mention 2 or 3 poems and yet only mentions 1 poem in the introduction. The student dives into a division of the poet’s themes based on stages of life without specifically mentioning the themes. As a reader I want to know what’s coming. Name the poems and name the themes. The intro is about getting into second gear. Start simple and build it up. You saw a blank page got a rush of blood to the head and just went for it. You need to be more mechanical. Slow down!
‘Advent’ is not mentioned in the introduction.
The fruits of this change in his world view is very prominent
innocence of a child whom can find wonder
The student has an obvious wardrobe full of vocabulary but seems to be too lazy to re-read his essay. The student should re-read his essay out loud before submitting in future as it does not flow well. The student should not simply lash down every fancy word he/she knows onto the page. The student is cooking dinner for 2 but laying a table for 50.
He attempts to re-experience the wonder and appreciate by his Advent sacrifices such as the "dry, black bread" and the "sugarless tea" inside the "advent-darkened room".
One cannot ‘attempt to re-experience the appreciate’. One can either appreciate or not appreciate. One can however attempt to re-experience the appreciation. Splitting of sentence required.
This poem gives off an aura of fulfillment, joy and hope for the future such as
Replace with ‘as indicated by’
His use of hyperbole shows that through his newfound appreciation of life the ordinary
Insert comma between ‘life’ and ‘the’
and plain such as a canal lock
Insert comma between ‘plain’ and ‘such’
The student contrasted the 2 poems well. Conclusion should have a paragraph of its own. The student is the Jarno Trulli of essay writing. The student shows the potential to be an A student but this requires consistency throughout.
P.S I’m not even too sure myself about the whole ‘appreciate’ thing above. I may not have read it right. Just that it doesn’t read right. I myself am too lazy to read back over it

P.P.S apologies for all the italics. Didn't copy well from word. Laziness prevents me from fixing it. Perhaps a nice mod could

I've never mentioned every poem I'm going to discuss in my intro, and I generally do very well in poetry essays. I don't think that's necessary, obviously there's nothing wrong with it but it's just not how I structure my essays. I do of course give an indictation of where I'm going to take an essay, but I don't list off poems in the intro...

partyatmygaff

Flecktarn wrote: »

That Kavanagh essay seems ridiculously short, how long was it?

Ah, that was the intro. It ended up being a few lines short of 4 pages. Got me a B3.

That last essay I wrote up got a B1. My teacher said it was an excellent intro though. I've never seen anyone mention every single poem they're going to discuss in their intro though.

pathway33

Deleted User wrote: »

I've never mentioned every poem I'm going to discuss in my intro, and I generally do very well in poetry essays. I don't think that's necessary, obviously there's nothing wrong with it but it's just not how I structure my essays. I do of course give an indictation of where I'm going to take an essay, but I don't list off poems in the intro...

the element of surprise....yes I'll agree many could live with that....Grade remains at C1

pathway33

partyatmygaff wrote: »

My teacher said it was an excellent intro though. I've never seen anyone mention every single poem they're going to discuss in their intro though.

On mature reflection perhaps I was a little hasty with my mention every poem demand. I would now say it's very possible to have a very legitimate intro without mentioning any poems but I like balance and if the essay is about 2 poems, why mention one in the intro and not the other?

Seannew1

Well there,

I appreciate your concern and it is fully true different english teachers will give different grades for the same essay, but I can fully reassure you this will not happen in the Leaving cert. The biggest gap most Leaving cert correctors in English especially at Higher Level will be 5% not 20%!!!! Examiners have to attend conferences, and the advising examiners will instruct the assitant examiners exactly what to expect in an answer and what to give good marks for etc!! In school, teachers tend to mark work down to keep you on your toes so don't worry to much about it. In english it's all about answering the question and in doing that expressing yourself as eloquently as possible!
best of luck,

Seán

MathsManiac

Seannew1 wrote: »

Well there,

I appreciate your concern and it is fully true different english teachers will give different grades for the same essay, but I can fully reassure you this will not happen in the Leaving cert. The biggest gap most Leaving cert correctors in English especially at Higher Level will be 5% not 20%!!!! Examiners have to attend conferences, and the advising examiners will instruct the assitant examiners exactly what to expect in an answer and what to give good marks for etc!! In school, teachers tend to mark work down to keep you on your toes so don't worry to much about it. In english it's all about answering the question and in doing that expressing yourself as eloquently as possible!
best of luck,

Seán

I believe that English is indeed marked more consistently than most people believe, and I'm fully aware of the processes involved in the Leaving Cert. However, I'm curious to know whether there is research data to back up the assertion that you made and that I've highlighted in bold above?

jumpguy

Yeah, when I was in class my teacher never liked my essays, and I'd always get a C. But I'd do grand then in mocks and exams. It's a matter of opinion as much as anything. If an examiner doesn't like a perfectly good essay, he/she probably won't be inclined to give it extra marks.

Seannew1

Well it goes back to the PCLM, the margin for error is so small here and remember 4 marks is 1 percent on the paper, for example 30% of marks go towards Purpose, so its pretty obvious an english examiner will know damn well if someone's answering the question or not.

MathsManiac

Seannew1 wrote: »

Well it goes back to the PCLM, the margin for error is so small here and remember 4 marks is 1 percent on the paper, for example 30% of marks go towards Purpose, so its pretty obvious an english examiner will know damn well if someone's answering the question or not.

But my point is that, as far as I'm aware, there isn't any recent published research on the accuracy with which examiners mark essays in the LC. Since you were quoting an actual percentage, I thought you might know of such.

This 5% assertion, then, is just an estimate based on your experience and beliefs about the system. Yes?

(I'm not saying it's wrong, by the way; I have no data on this matter either.)

And when you say the margin of error is small in the PCLM system, how small do you mean, and how do you know?

Seannew1

MathsManiac wrote: »

But my point is that, as far as I'm aware, there isn't any recent published research on the accuracy with which examiners mark essays in the LC. Since you were quoting an actual percentage, I thought you might know of such.

This 5% assertion, then, is just an estimate based on your experience and beliefs about the system. Yes?

(I'm not saying it's wrong, by the way; I have no data on this matter either.)

And when you say the margin of error is small in the PCLM system, how small do you mean, and how do you know?

No, but even out of appeals, it is rare people would go over 5% in any case. You have to remember the person you will be marking your english paper this summer has 15 yrs of correcting lc papers and they know evert detail of every novel, play etc.

Even in English, you'll notice examiners follow a pretty rigid marking scheme. On your question about the PCLM, an example is the Prescribed poetry question, the grading is P15, C15, L15 and M5, take the question on Bishop, if a student answers the question then they'll score high but they'll be crucified in the rest of the marking if they don't and 2 examiners aren't going to give someone with excellent spelling 1/5 or 5/5 in the same essay.that's what I mean about the margin of error is very small.
Hope that helps.

MathsManiac

Seannew1 wrote: »

No, but even out of appeals, it is rare people would go over 5% in any case.

This doesn't consitute relevant research. The appeal examiner sees the marks the original examiner awarded. Therefore it is impossible for them to take a completely independent view of the work, even if they wanted to. Furthermore, in the case of subjective assessments, they are instructed not to change the original mark unless it is significantly out of line with their own judgment.

By relevant research, I mean systematic research in which examiners mark the same essays completely independently of each other.

Seannew1 wrote: »

You have to remember the person you will be marking your English paper this summer has 15 yrs of correcting lc papers and they know evert detail of every novel, play etc.

I don't doubt this, but the same would be true about comparable examiners in other countries, and I'm not aware of any examination board claiming to have established such levels of accuracy in essay marking as you have described.

Seannew1 wrote: »

Even in English, you'll notice examiners follow a pretty rigid marking scheme. On your question about the PCLM, an example is the Prescribed poetry question, the grading is P15, C15, L15 and M5, take the question on Bishop, if a student answers the question then they'll score high but they'll be crucified in the rest of the marking if they don't and 2 examiners aren't going to give someone with excellent spelling 1/5 or 5/5 in the same essay.that's what I mean about the margin of error is very small.
Hope that helps.

You've indicated here that what you mean by a small margin of error is that it's unlikely that two different examiners would give 1 out of 5 and 5 out of 5 for the same aspect of a piece of work. I infer that you therefore consider 2, 3 or 4 out of 5 to be conceivable from different examiners. A mark that could range from 40% to 80% of the marks available could hardly be described as a 5% margin of error.

If we take the midpoint between 1 out of 5 and 2 out of 5 as the boundary of your suggested error range, and similarly at the upper end, and if comparable levels of disagreement are feasible under the P, C and L headings, then the total mark for the essay could range from 15 to 45 out of 50. This is a range from 30% to 90%. If you read this as 60 [+/-] 30, it's a 30% margin of error, quite a distance from your first suggestion.

In order to establish a 5% margin of error, as you first suggested, we would need to see evidence that if all examiners were to independently mark an essay scored out of 50 marks, then 95% of them would give a total mark that is within 2.5 marks of the correct score.

I believe this is unlikely to be true, but I would obviously accept it if someone had solid data to back it up. I don't know whether SEC does this kind of research. I was a maths examiner for a number of years and I was never asked to participate in such research or made aware of it, so I'm guessing they don't. They certainly don't publish anything like this on their website.