Project write-ups



You may NOT consult each other..

However, you ARE allowed

  • to use calculators
  • to consult the internet (including this site)
  • to use your notes
  • to use textbooks




Design

Planning the most appropriate observing programme for the chosen task, including observing sites, times, instruments needed, and the need for repeat observations.

Here are the board's criteria for Design

0

No procedure designed.

1

Outline a simple procedure for the observations, using basic astronomical terminology.

23

Astronomical knowledge and understanding used to decide on the most appropriate site, time, equipment and observations.

Spelling, punctuation and grammar used with reasonable accuracy. Limited use of astronomical terminology.

45

Detailed astronomical knowledge and understanding used to design the mosts appropriate observing programme with a range of sites, times and instruments evaluated.

Spelling punctuation and grammar used with considerable accuracy. Good range of astronomical terminology used correctly.


Observation

The record of the range of observations taken, including any drawings of the objects observed, details of the observing session (weather conditions, location, etc.).


0

No observations completed.

1

Simple observations completed, providing some data.

A few observational details completed.

23

Sound observations completed and recorded, providing adequate data for the task.

Clear an accurate observational details included.

45

Excellent programme of observations completed and recorded, providing conclusive data for the task.

Full observational details included clearly and accurately.


Analysis

The conclusions drawn from the observational data collected, related to the observational task chosen.

Here is what the board says about Analysis

0

No analysis on the observations

1

Simple comments on what is shown by the observations, using basic astronomical terminology.

23

Conclusions or calculations derived from observational data used to address the task set.

Spelling, punctuation and grammar used with reasonable accuracy. Limited use of astronomical terminology

45

Full analysis of the observational data, resulting in clear conclusions relating to the task set.

Spelling punctuation and grammar used with considerable accuracy. Good range of astronomical terminology used correctly.


Evaluation

An evaluation of the data collected in the observation and suggestions for improvements or extensions to further observations.


And here is what it says about Evaluation

0
No evaluation of the observation
1
Simple comments on the accuracy of the observations, using basic astronomical terminology.
23

Supported statement of the accuracy of the observational data obtained.

Feasible suggestions for improvements or extensions to the observations.

Spelling, punctuation and grammar used with reasonable accuracy. Limited use of astronomical terminology

45

Clearly reasoned quantitative assessment of the accuracy of the observational data obtained.

Detailed suggestions for improvements or extensions to the observations.

Spelling punctuation and grammar used with considerable accuracy. Good range of astronomical terminology used correctly.


You will notice that the last paragraphs in each of the 23 and 45 boxes are the same. The way the assessment works is this
  • If simple comments are present, using basic astronomical terminology, then I award at least 1 mark, and I move on to consider the 23 mark criteria. I don't imagine you will have any trouble surmounting this hurdle but note that it requires comments AND using some astronomical vocabulary.
  • If none of the 23 mark criteria are satisfied, I revert to the 1 mark already awarded
  • If some of the 23 mark criteria are satisfied, but not all, I award 2 marks
  • If all of the 23 mark criteria are satisfied I award 3 marks, and I move on to consider the 45 mark criteria.
  • If none of the 45 mark criteria are satisfied, I revert to the 3 marks already awarded
  • If some of the 45 mark criteria are satisfied, but not all, I award 4 marks
  • If all of the 45 mark criteria are satisfied I award 5 marks.
You will notice that this is a completely different approach to ticking correct things and then adding the ticks up at the end. You need to tackle the task of writing up with all this in mind. You have to serve up on a plate to the external examiner precisely where you have satisfied the criteria. So, for example, you need a heading "Analysis" and, later, another heading "Evaluation". Within the "Evaluation" heading, you need an "Accuracy" sub-heading and an "Improvements & Extensions" sub-heading.


Notes on Planning

These will follow tomorrow, I hope.


Notes on Analysis

We are likely to have discussed in some detail how to extract significant information from your observations. If you follow those discussions through, you are likely to qualify for the first paragraph of the 45 mark criteria.

To cope with the "good range of astronomical terminology", I recommend finding the relevant section in the textbook, making a list of all the words that look as if they might fit the bill, and then making sure that you incorporate those words into what you write.

You will start with the sheets of paper that you completed in the field while taking your observations. This sheet of paper, in its raw form, will form part of your presentation. You might make measurements from this sheet, in which case you will put these into a suitable table, with appropriate headings, etc. If you do this, you will need to provide a description of precisely what you did to obtain these measurements, and specify the instruments that you used. You will probably use these figures to calculate something. You will need to provide an outline of the theory of what it is that you are calculating - notes on this website might point you in the right direction - but what you write has to be in your own words.


Notes on Evaluation - 1st sentence

Suppose you are measuring the speed at which a friend is able to run. You set out a track for them to cover, and then you time how long it takes them to run that distance. You do this six times, obtaining the results:
10 s, 11 s, 10 s, 9 s, 11 s, 12 s. The average (technical word: mean) of these times is 10.5 s, and you want to give an indication of the spread, or how close to each other the readings are. The easiest thing to do is to notice that the difference between the highest and lowest is 3s, and that they lie 1.5 s away from the mean. The 1.5 s is called the uncertainty. So you could say

mean time to run the course = 10.5 s 1.5 s

Rather better is to express the uncertainty as a percentage of the mean, which you do by dividing the mean into the uncertainty and multiplying by 100. In this case it comes out at a little over 14%, so you would say

mean time to run the course = 10.5 s 14%

Whenever you end up with several versions of a reading that ought to be the same, you should calculate a mean and percentage uncertainty. It may seem complicated, but that is what the word "quantitative" means in the first sentence of the Evaluation criteria for 45.

In order to find your friend's speed, you need to know how far they ran, and then divide the time into that distance. So you might both pace the course out, and come up with the (different) answers 85 m and 81 m. Proceeding as before, you would calculate

mean distance run = 83 m 2.4%

[Make sure you can do this calculation and that you agree with this answer]

Now it's time to calculate the final result. So we say that the speed is the mean distance run divided by the mean time taken, which comes out at 7.9 m/s. [Ensure that you agree with this.] But before we can give the answer to a startled world, we need to be able to say how reliable the answer is. So we add the percentage uncertainties of the distance and time, which comes to about 16%. Lastly we work out what 16% of 7.9 is (it comes out at around 1.3 check this), so that we say, finally:

Our friend's speed is 7.9 m/s 1.3 m/s

and we confidently expect that the examiner will remain focused on the 45 box! If you read the first sentence in each of the three boxes in the Evaluation table, you will appreciate why you have to go the whole hog.


Notes on Evaluation - 2nd sentence

This is both easier and harder to deal with. Here are some thoughts:
  • It might be that, while you were analysing your readings, you found yourself saying something like, "I wish I'd taken more care with this or that aspect of recording the data". If so, then that will give you an obvious way of suggesting improvements. But beware of just saying "Take more care". You have to specify just what you would have done differently which would have resulted in 'better' readings.
  • It is always possible to improve matters by taking more readings. In the notes above, we have arrived at our percentage uncertainties by an extremely crude method. What we should do is to calculate what is called the standard deviation and then divide by the square root of the number of readings to arrive at what is called the standard error. It should be reasonably obvious that if you have a larger number of readings, then the standard deviation would then be divided by a larger number, which would make the standard error smaller. If our percentage uncertainty is smaller, then we have a more reliable result. Job done.
  • Some projects offer several different ways of dealing with observations. If several approaches are possible, and you have opted for approach A, then explaining how approaches B and C would work can be a sensible thing to do, outlining both the new methods of analysis and the changes in observational procedure that would have been necessary.
  • Suppose that you are doing a physics experiment in which you are measuring a resistance with the formula voltage/current. You take several readings of voltage and current, and for each you work out the resistance. Then you work out the mean and percentage uncertainty as explained above. An alternative approach would be to plot a graph of voltage against current, draw the best-fit line and then take the gradient. Then you can draw the steepest and shallowest straight lines that your data points will let you get away with, find their gradients, and use those to generate a percentage uncertainty of the gradient. So you could explain that alternative procedure without actually carrying it out.
  • Very often, the quality of observations could be improved by using a telescope and/or camera. Then you can enlarge photographs, take careful measurements (which are much easier on a photograph in a warm brightly-lit room later on than out in the field in the cold darkness!). Of course, if it was an unaided project, you wouldn't have been allowed to do this but that doesn't invalidate it as a suggestion for improving the observations in an ideal world.