Written Style

The writing style is terse, factual, and objective. It is - for lack of a better word - scientific.

Notice the differences between the two examples below, where the one on the right-hand side adopts a more correct style of writing, suitable for a laboratory report.

“I did all the measurements and found that g was similar to the value in Young and Freedman. The equipment did not behave itself properly and so errors crept in. My best value was 9.7 ms-2. I think I could have improved this value if I had more time.”

“The acceleration due to gravity, g, was measured and compared with the accepted value¹. Systematic uncertainties were accounted for, yielding a value of 9.7 ±0.1 ms^-2. Further studies yielding a larger data set would clearly reduce the standard error on this result but accuracy would not improve.”

The best way to get a feel for the style is to read lots of scientific articles. Good examples are journals from the American Physical Society, such as the Physical Review Letters (use your university login for free access). You probably will not understand too much of the physics content, so focus on the style in which it is written.

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

Key Points

Include all necessary details and calculations. The main body of the report should be written for someone who is somewhat familiar with the equipment but does not have access to the laboratory script.

Do not present opinions/speculations as facts without providing evidence to support it. Be precise and unambiguous.

“This is a reliable result” – Reliable in what way? For what purpose?
“At high frequencies the wires and oscilloscopes have a capacitance.” – No; they have a capacitance at all frequencies, but the effect of the capacitance becomes significant at high frequencies. What qualifies as a “high frequency” in the context of the experiment?
Your text is not mathematical. Spell out the mathematical symbols:
- “where g = gradient” -> “where g is the gradient”
- “taking the log of N” -> “taking the (natural) logarithm of N”

Quick Tips

“Data” is the plural form, so make sure to write as “The data are…”
“Calculated” and “measured” don’t mean the same thing.
An “accepted value” is not necessarily “theoretical.”
Use “we/our” rather than “I/my”.
“Using LINEST” is meaningless to anyone who does not use Excel and “scipy.optimize.curve_fit” is meaningless to anyone who doesn’t use that particular Python package. Instead, refer to these as least-squares fitting on the data.
Equations are part of the text, so use punctuation accordingly. More on equations can be found here, (Equations Symbols and Units Page Link).
Unless they are numerical results or contained within 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).
You must define any symbol representing a physical quantity the first time it is used, even if it seems obvious. For instance, if you use the symbol c to denote the speed of light, you need to tell the reader so!

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 m^1/2 .

(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 m^1/2 .

(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 m^1/2 .

(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: m^1/2 .

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.”

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.