This what?
This (these, that, those) allows you to point to people and things.
- You can use this with a noun ("This method")
OR - You can use this by itself--as a pronoun ("This worked well for group A")
If you use this by itself (as a pronoun) in a more complex text, the reader can quickly get confused–they won't be able to easily see what you are pointing at.
Choosing to use this with a noun (this analysis) rather than by itself (this) allows you to point back to one specific part of the previous text.
Add a specific word
To use this clearly, just add a word that points to the specific part of the last sentence that you want to connect to. Otherwise, you may inadvertently point back to multiple options and the reader may think "this WHAT?"
The more complex the sentence, the more difficult it will be for the reader to make the connection--to understand what this is referring to. They will have to go back and re-read and try to figure out the ambiguity on their own.
These cells were washed...
We chose
We chose this analysis because...
This assessment gave us...
This approach/The internal approach is different from the external approach.
Restructure
Move around the information in the sentence:
We injected 5mL of the drug twice daily.
We injected the dosage preferred by veterinarians: 5mL twice daily.
Use a relative clause instead of this:
Parts of the selected literature may reflect different values than the standards of the jurisdictions–
Parts of the selected literature may reflect different values than the standards of the jurisdictions, which may limit my assessment.
Paraphrase
Sometimes you can remove this altogether and paraphrase the part that you want to refer to:
As a result, this country has a high and still increasing number of political parties, which are generally unable to achieve a majority in elections.
As a result, this country has a high and still increasing number of political parties, which are generally unable to achieve a majority in elections. Having so many political parties makes multiparty coalition governments inevitable.
Various therapeutic strategies have been developed to alleviate the symptoms and reduce the severity of COVID-19.
In this paper, I will reflect on the dialogue between “internal” and “external” research.
Check agreement
Make sure that this refers to a singular thing and these refers to a plural thing.
We used methods A and B for analysis.
We used methods A and B for analysis. These analyses were chosen because...
Why does this level of precision matter?
Readers expect to easily see the relationships between sentences. Using specific language reduces ambiguity and improves flow. Your reader will not have to re-read and work to figure out what you are referring to if you simply tell them each time.
So look closely at every instance of this and add a couple of extra words to help the reader understand exactly what you are referring to!
Show relationships explicitly. Avoid vague phrases like the above-mentioned comment or the aforementioned things and reader-stopper constructions like respectively, former and latter.
How important is this level of precision?
On a scale of 1-10, it's an 8: pretty important. You can sometimes (rarely!) get away with using this by itself without confusing the reader but you will want to specify what you are referring to most of the time.
Are you struggling to remove this? Ask for help!