Across, throughout or through? Draw it and the choice makes itself

You are writing a sentence:

We observed consistent performance ____ architecture generations.

And your hands stop. through? throughout? across?

The dictionary makes it worse, because all three come back with roughly the same set of glosses: through, across, all over, all the way. So you pick one, ship it, and never find out whether it sounded native.

Close the dictionary. These three words do not differ by meaning. They differ by shape.

Three words, three shapes

Once they are drawn, they stop looking like relatives:

Word	Shape	What it describes
through	a path	a route, in one end and out the other
throughout	a filled volume	presence, every part of the inside has it
across	a bar spanning columns	scope, spread over several things at the same level

through: there is a route

through is the original, and it stresses the path. Something moves, there is an entry, there is an exit.

Data flows through the pipeline. The request goes through several stages. She walked through the tunnel.

Ask yourself: is anything actually travelling? If yes, through.

throughout: filling the inside

throughout drops the movement entirely. It is about being present everywhere inside something.

Caching is enabled throughout the system. This mechanism is used throughout the network.

This is where throughout and through get confused, since they are three letters apart. Put them on the same object and the difference is impossible to miss:

The token passes through the transformer. One token, moving from input to output. Positional encoding is used throughout the transformer. Nothing is moving. Every layer simply has it.

throughout also works on time, because a stretch of time is continuous enough to fill:

The service was available throughout the day.

across: spanning separate things

across needs several separate items at the same level. It reaches over all of them.

The trend is consistent across models. We ran the same test across datasets. This policy applies across teams.

GPT-2, GPT-3, GPT-4, Llama, Gemma. Five names, five distinct things, all peers. That is across territory.

Back to the sentence

We observed consistent performance ____ architecture generations.

architecture generations means Gen 1, Gen 2, Gen 3, Gen 4. Four separate generations, all peers. So the answer is across:

We observed consistent performance across architecture generations. ✅

And throughout architecture generations is wrong for a reason that is purely geometric:

throughout needs something continuous to fill: a whole system, a whole network, a whole day. Architecture generations are discrete. There is nothing between Gen 1 and Gen 2 to fill in. No inside means nothing for throughout to hold on to.

The shortcut

Before choosing, ask one question: what shape is the thing after it?

Shape of A	Word	Example
A pipe, a process, a sequence of steps	through	the request passes through the pipeline
A continuous volume, a system, a stretch of time	throughout	caching is enabled throughout the system · available throughout the day
Several separate items, all peers	across	across models · across datasets · across teams · across architecture generations

Compressed: through is along a route, throughout is everywhere inside, across is over many.

The takeaway

These three are hard not because of grammar but because bilingual dictionaries flatten them into one word. Drop that word and ask instead: is the thing that follows a line, a volume, or a row?

Answer that and the choice is already made.

Knowing how to choose and choosing without thinking are still two different skills. Native speakers are not sketching diagrams in their heads. They have heard across models thousands of times, so throughout models sets off an alarm instantly. That is the part you have left, and it is where EasyDictation helps: real videos, typed back phrase by phrase, so prepositions land in your ear before they land in a rule table.