Omission of "and"

[shravani407]

Hi,

I'm a bit confused on the usage of "and" in sentences such as this one:

"The new design was more intuitive and user-friendly, reducing user errors" (source: english.stackexchange.com)

Can't this be written as: "The new design was more intuitive,user-friendly and reduced user errors" ? or "The new design was more intuitive, user-friendly and thus reduced user errors" ? What is the rule behind the usage of "and" in such instances? Would appreciate if you can give me more examples.


Thanks

[RonPurewal]

conveniently, i've written about this exact thing before:
post108571.html#p108571

[RonPurewal]

also, the same distinction ("and" versus __ing modifier) was the topic of the march 26, 2015, episode of "thursdays with ron".

https://www.manhattanprep.com/gmat/thursdays-with-ron/
scroll down for the archive.

[RonPurewal]

so, this sentence ...

"The new design was more intuitive and user-friendly, reducing user errors"

... would not show up on the GMAT, because there are two equally reasonable possibilities:

1/
the reduction in user errors WAS DUE TO the "intuitive and user-friendly" quality of the new design (= cause-effect relationship).

2/
there was not, in fact, a cause-effect relationship; these are independent observations. ("The users liked the new interface more. Oh, by the way, they made fewer errors, too.")

if the intended meaning is #1, then the sentence is correct as written.
if the intended meaning is #2, then the sentence as written has the wrong meaning (because it means #1, and #1 is not #2). if this is the case, then "and" (or "furthermore", or "in addition", or any of a zillion other similar connectors) is more appropriate.

if you face this issue on the GMAT, you won't see a situation like this one (in which both #1 and #2 are plausible). rather, if this is an issue, you'll be presented with a situation in which only one of #1 and #2 is plausible, and the other is absurd/illogical/self-contradictory.
(for examples of a firm distinction, see my link above.)

[RonPurewal]

Can't this be written as: "The new design was more intuitive, user-friendly and reduced user errors" ?

no.
even if the intended meaning is in line with this (#2 in the post above), this sentence has bad parallelism.

you can try to read this parallel construction in two different ways... but both of them fail.

The new design was more intuitive, user-friendly, and reduced user errors
ADJ, ADJ, and VERB
nope.

The new design was more intuitive, user-friendly, and reduced user errors
VERB, ADJ, and VERB
still nope.

(also, if you're going to put these 3 items in parallel, you need to put another "more" in front of "user-friendly". in the original formulation-- "more intuitive and user-friendly"-- it's clear that "more" applies equally to both descriptions.)

[RonPurewal]

"The new design was more intuitive, user-friendly and thus reduced user errors" ?

this sentence has the same issues enumerated in the last post.