# Report writing guidance

## Written Style

You should aim for simplicity, concision and clarity. Be precise and choose your words carefully.

#### Key Points

• Include all necessary details and calculations. The report should be written for someone who is somewhat familiar with the equipment, but does not know of your method.
• Do not present opinion or speculation as fact. Be precise andunambiguous
• "This is a reliable result" - Reliable for what purpose?
• "At high frequencies the wires and oscilloscopes have a capacitance." No: they have a capacitance at all frequencies and the effect of this capacitance becomes significant at high frequencies. And what do you mean by "high frequencies"?
• "Calculated" and "measured" do not mean the same thing.
• "The resistance was obtained by graphing the voltage and current and then using LINEST to find the gradient". This is ambiguous and no good.
• You do not need to graph something to calculate a proportionality ratio, suggesting that this is the case is confusing.
• "Using LINEST" is meaningless to anyone who has not used Excel. Introducing it as a part of Excel would suggest that LINEST specifically is necessary to do this, which it is not. Instead, you should say something like "The resistance was obtained using least-squares fitting of a straight line to the experimental distribution of voltage against current, giving the resistance as the gradient of said line".
• Equations are part of your text, not a separate entity like figures. For more on equations, click here.
• Your text is not mathematical though, e.g.:
• say "where g is the gradient" not "where g = gradient"
• say "taking the logarithm of N" not "taking the log of N"
• Unless they refer to numerical results or are parts of mathematical expressions, numbers below ten are usually written in full (“the three readings averaged to 3 μs”). Use numerals for larger numbers (“the 12 readings averaged to 3.2 μs”).
• Names of elements or compounds normally start with a small letter, not a capital letter – e.g., “a silicon diode”, not “a Silicon diode” (and definitely not a “silicone diode”, silicone is a polymer).
• For clarity, you need to define any symbol representing a physical quantity the first time it is used, even if you think that its meaning is quite obvious. For instance, if you use the symbol c to denote the speed of light, you need to tell the reader that c is the speed of light.

You can find more about the written style expected from lab reports under section 3 in the level 1 guidelines.

## Punctuation

Compare the following sentences:

(a) The angular frequency of motion is (k/m)1/2, where k is the force constant of the spring and m is the mass of the body. The period of oscillation is therefore proportional to m1/2 .

(b) The angular frequency of motion is (k/m)1/2. Where k is the force constant of the spring and m is the mass of the body. The period of oscillation is therefore proportional to m1/2 .

(c) The angular frequency of motion is (k/m)1/2, where k is the force constant of the spring and m is the mass of the body, the period of oscillation is therefore proportional to m1/2 .

(d) The angular frequency of motion is: (k/m)1/2, where k is the force constant of the spring and m is the mass of the body. The period of oscillation is therefore proportional to: m1/2 .

The punctuation is correct in (a). In (b) a full stop is incorrectly used in lieu of a comma. In (c) a comma is incorrectly used in lieu of a full stop. In (d) the colons (:) are superfluous.

#### Other points to note:

• “It's” means “It is” or “It has”. The possessive pronoun is “its”, as in “its value”. In any case, avoid contractions such as “it's”, “hasn't” or “doesn't” in formal writing.
• Avoid colloquialisms, too as in “Hubble came up with a value of H0” (instead, write “Hubble obtained a value of H0” or equivalent). Reports need to be written carefully and in more formal English than many people would use in everyday life.
• The word “principal”, as in “the principal quantum number”, is not spelled “principle”, as in “the Principle of Least Action” and “the principles of this method”. The word “complement”, as in “these results complement those obtained using the other method”, is not spelled “compliment”, as in “she returned the compliment”.
• Data is the plural of datum but is often used as a singular (e.g., “this data shows ...”). However, using this word as a plural has the preference of many careful writers, at least in British English (e.g., “these data show ...”).
• American spellings are acceptable but British spellings are preferred; however, be consistent and do not mix American and British spellings. Use a spell checker to help you with the spellings; however, remember that spell checkers won't be able to spot what's wrong in, e.g., “the geranium diode”.

## Apostrophes

When should you use an apostrophe?

You use an apostrophe to indicate where you have omitted letters from a word, or even a complete word, for brevity.

#### Example:

Without using any apostrophes:

“Sheila has taken her own dogs and many of her friends dogs for numerous walks.”

With apostrophes:

“Sheila’s taken her own dogs and many of her friends’ dogs for numerous walks.”

In the explanation that follows we introduce the correct use of double and single inverted commas. An explanation of this comes later (vide infra, meaning “see below”.)

The first apostrophe indicates that the word “has” has been omitted. The second one needs more explanation. We use the apostrophe at the end of words when we are referring to a plurality. In this case Sheila has many friends whose dogs she walks. The word ‘omitted’ here is the word “their” so that we would have written: “….many of her friends, their dogs, for numerous walks.”

Alternatively, Sheila may only have one friend whose dog she walks. In this case we would have written: “….and her friend’s dogs for numerous…..”. The omitted word here is “her” so that we could have written: “…..and her friend, her dogs, for numerous…..”.

In the singular case, the word omitted may be; ”has” (as in; “Sheila’s taken”), “her” (as in; “Sheila’s dogs”), “his”, “is” (as in; “…it is…”), or “its” (as in; “...this Pizza’s cold…”)

So now you can see that when “Pizza’s” and “Kebab’s” are advertised for sale you might want to know just what it is that Pizza and Kebab have that is being sold (get it?)

## Inverted Commas

This is quite simple. In the previous section, double inverted commas are used when we mean to indicate that something is literal. In other words exactly how we mean it to be presented. So when we used “Pizza’s” we really meant that this is how you would see it (with the incorrect use of the apostrophe) on a shop sign. When we use the single inverted commas as in ’omitted’, we meant that we did not mean that the word had been literally omitted.