O lvl: Combined Sciences vs Pure Sciences

eagle SG

To me, combined sciences is actually tougher on the student... This is why:

combined physics is roughly about 75% of pure physics
combined chem is roughly about 75% of pure chem

so if you take pure sciences, your workload is 100% + 100% = 200%
if you take combined sciences, your workload is 75% + 75% = 150%

But the thing is... for pure sciences, it is 200% for two subjects
for combined sciences, it is 150% for only one subject!!!

It is this reduction of about 50% in workload that makes school tell students to drop to combine sciences, but the problem is that the student has to deal with more content for less subject grades.

What do you all think?

Darkness_hacker99 SG

The combined sciences syllabus is designed in such a way, it's to provide broad-based understanding of the subjects(chem, bio, understand) in relation to our daily lifes. Students taking combines sciences will be able to apply knowledge gained to everyday life, and understand how the subj have an impact on human.

In the past, my school doesn't offer pure sci for NA students. Yea, in order to excel for both Science(Chemistry, Biology), I read up the pure Chem & Bio textbook and assessments book myself. I've gained a deeper understand of how stuffs work.

Y_Shun SG

but why not you contribute another 50% just for 2 grades? (:

Instead of getting full 150% just for 1 grade.

UltimaOnline SG

Yes, this is a matter on which I've advised many students on, for many years now.

The advantage Pure Science has over Combined Science is :

1) More H2 subject opportunities at 'A' levels.

2) One of your sciences won't 'pull down' or 'sabotage' the other science.

The advantage of Combined Science over Pure Science is :

1) Much easier to pass and/or score A1.

So, ultimately, the decision to take Pure vs Combined, depends on several factors, including the student's desired career path and desired 'A' level subject combination, as well as the student's competence in one or both Sciences.

If a student is generally weak in science, he should (or from the school admin's perspective, he has no choice but to) take combined science. However, he should be careful to choose a combined science combination that does not sabo himself (eg. if he's lousy in Physics, he should take cobined science Chem + Bio, instead of combined Phys + Chem).

However, all students interested in a career in Science rather than Arts or Commerce, must compulsorily study the Pure Sciences at 'O' levels, and H2 Sciences at 'A' levels. Else their planned career in the Sciences may be jeopardized. (eg. To study Medicine, you need distinctions in H2 Maths, H2 Chem, and either H2 Physics or H2 Biology; so at 'O' levels, you should be taking Pure Chem and Pure Physics or Pure Bio; or better yet, Triple Pure Science.)

eagle SG

Hi Ultimaonline,

regarding this

The advantage of Combined Science over Pure Science is :

1) Much easier to pass and/or score A1.

What I meant was that it is actually harder to score A1, because the workload for this one single grade is higher.

UltimaOnline SG

Hi Ultimaonline,

regarding this

What I meant was that it is actually harder to score A1, because the workload for this one single grade is higher.

Hi eagle,

That point is already covered by my

>>> 2) One of your sciences won't 'pull down' or 'sabotage' the other science. <<<

In other words, as long as both your physics and chem are strong, it's much easier to score A1 in combined phy+chem, compared to pure phy, or pure chem.

But if one of ur sciences (eg. phy) is weak, then you're shooting urself in the foot by taking combined phy+chem. Coz ur phy may pull down ur chem.

So it depends on the student, if he's good enough in both sciences, then taking combined science would give him a higher chance of passing and/or scoring A1 (compared to pure). But if he's really good in science (and he wants a career in science), then he must take pure sciences.

UltimaOnline SG

To elaborate,

Most combined science students who score A1 for phy+chem, would probably score B3 for pure Phy and B3 for pure Chem. This is probably (and ironically) not due so much to the greater difficulty of the Pure vs Combined, but more to the bell curve grading (seeing how thousands of top students in Sg are all taking Pure).

eagle SG

Actually my issue is.... schools normally want students who are weaker in science (or sometimes, weaker in studies) to move from pure to combined... which is dumb

E.g. http://www.sgforums.com/forums/2297/topics/345411

Then she dropped pure Physics and Chem. Now taking combined Physics/Chem plus Biology as she is interested in the life sciences.

Like you said

In other words, as long as both your physics and chem are strong, it's much easier to score A1 in combined phy+chem, compared to pure phy, or pure chem.

But if one of ur sciences (eg. phy) is weak, then you're shooting urself in the foot by taking combined phy+chem. Coz ur phy may pull down ur chem.

Schools are actually killing students sometimes....

eagle SG

To elaborate,

This is interesting...

I think I roughly see the diff now.....

Workload is higher for 1 subject grade, but it's easier to score because the cohort taking combined science is usually weaker in science

d3sT1nY SG

Actually I feel that whether the student is good in that particular science or not is not solely dependent on his/her 'O' level science grade.

As in 'O' level science is just the surface of the subject itself. It doesn't really delve deep into the subject so the student may or may not like the subject after further studying it in poly or JC.

It's like 'O' level biology coordination and response chapter. It teaches you how the signals are transferred from the hand to the brain and then back to the muscles in layman's term.

But in JC level, you will need to know the opening of pores or whatsoever openings for the sodium ions to pass through into the synapse in order for the signal to be transferred.

This is what I feel lah. Haha.

UltimaOnline SG

It's like 'O' level biology coordination and response chapter. It teaches you how the signals are transferred from the hand to the brain and then back to the muscles in layman's term.

But in JC level, you will need to know the opening of pores or whatsoever openings for the sodium ions to pass through into the synapse in order for the signal to be transferred.

Yes, that's the sodium-potassium pump required to maintain the resting potential. This requires ATP. The action potential (ie. the nerve impulse itself), in contrast, does not require ATP. This may come as a surprise to 'O' level students.

For 'O' levels students planning to take H2 Biology, here's a sneak peak at what you'll be studying for this chapter in the JC :

Sodium-Potassium pump :

http://en.wikipedia.org/wiki/Sodium_potassium_pump

Action potential :

http://en.wikipedia.org/wiki/Action_potential

The JC is the good life.

2cansam SG

i had problems tackling pure sciences in secondary school due to greater in-depth coverage of each subject matter.

The questions demand a higher level of thinking than combined science papers, thus i had trouble scoring A's for it.

The difficulty in scoring for pure papers prompted me to drop pure sciences and take up combined science

UltimaOnline SG

This is interesting...

I think I roughly see the diff now.....

Workload is higher for 1 subject grade, but it's easier to score because the cohort taking combined science is usually weaker in science

Yes, my point exactly. Just in case any student is confused about what we've been discussing, let me put it this way :

In Combined Science (eg. Phyiscs/Chemistry), to score A1, you need about 75% marks.

In Pure Sciences (eg. Physics, Chemistry), to score A1, you need about 90% marks.

This is due to the Bell-Curve, in which all the raw scores are arranged from highest to lowest, and only the top X% gets A1, the next Y% gets A2, and so on.

And the tens of thousands of top students (who score 7A1s) all take Pure Sciences, which is why the A1 grade is pushed up (eg. to 90% marks).

UltimaOnline SG

i had problems tackling pure sciences in secondary school due to greater in-depth coverage of each subject matter.

The questions demand a higher level of thinking than combined science papers, thus i had trouble scoring A's for it.

The difficulty in scoring for pure papers prompted me to drop pure sciences and take up combined science

Yes, greater depth and higher level of thinking, PLUS the bell-curve (see my post above), makes the Pure Sciences a lot tougher to pass and/or score, compared to the Combined Sciences.

Nonetheless, all students interested in a career in the Sciences and must therefore compulsorily take Sciences in the University and must therefore compulsorily take H2 Sciences in the JC and must therefore compulsorily take Pure Sciences at 'O' level, have no choice but to stick to Pure Sciences, and find ways to improve your grades (eg. come to my tuition for Chem/Bio and Eagle's tuition for Physics/Maths).