The American had a difficult start to a schedule dominated by unfamiliar venues and tricky street and temporary tracks that saw him involved in a string of incidents as he struggled to keep up with team-mate Alex Albon.
However, in Austria he had a strong run to 13th in a race of low attrition, while at Silverstone he finished 11th and just four seconds behind the Ferrari of Carlos Sainz.
Robson acknowledged that the return to Europe and tracks that Sargeant knows and which have a little more margin for error has been a boost for the youngster.
"I think that makes a difference,” he told Autosport. “And at the same time though, there is just that learning, that experience, good or bad, I think it all is really valuable. So hopefully things are just starting to come together.
“I think the next two will be really interesting. They are circuits he knows, circuits that he should be quite good at.
“The pace of the car will fluctuate a little bit maybe. From a mindset point of view, I think if the pace of the car is off a bit, then that's another good learning experience.
“He's got to keep up with Alex in a race where we're less competitive, which is a slightly different kind of mental state he's got to control and get through.
“Or ideally, if the car is actually just quicker than we think he might be, then he won't have to deal with that. But it's good learning.”
Sargeant’s drive at the Red Bull Ring went largely under the radar as he finished well outside the points, but Robson agreed it was a good performance that was repeated at Silverstone.
“I think by far and away Austria was his best race to that point,” he noted. “I think to then come to Silverstone and back that up, he did a sterling job.
“I think his lap under pressure in Q1 after the red flag, having queued up, that was exceptionally good as well. And the kind of thing that a few races ago he may have not been able to cope with.
"The race was very good. And it wasn’t easy, particularly the first 10 laps when there was a bit of drizzle and wind, and it was difficult to manage the tyres and just to build a nice pace.
“But he got through all of that. And his pace wasn't far off Alex at all, and Alex was running the new front wing, and not Logan.
“I think these two weekends have been really good, and hopefully mark a clear turning point."
Robson acknowledged that Sargeant won’t always have a strong Friday as a launching pad for the weekend, which was the case at Silverstone, where he was fifth in FP2.
“Hitting the ground running on Friday definitely makes a big difference. Hungary will be a bit more difficult with that, because we have fewer sets of tyres [under the alternative allocation rules].
“I think he's not going to have that luxury, so it is going to be more difficult. But again, it's another box to tick, isn't it?”
