It's hard for me to explain, getting people to open up is kind of something I've always been good at, but I think the best advice I can give is to be curious, a bit venerable, and ask open ended questions. Another trick I like is to kind of put words in their mouth and let them correct me (kind of like Cunningham's Law - https://meta.wikimedia.org/wiki/Cunningham%27s_Law)
So for example a conversation may go like this:
-----
Me: Hey, so you've been on project X for a month now. How are you feeling about it?
Report: It's good.
Me: I know this is the first time you're using Y technology. Are you finding the ramp up easy?
Report: Yeah. It's not too bad.
Me: That's great! I remember when I was working in that codebase it took me forever to understand Z component. What did you think of that?
Report: Oh, yeah. I worked in there, it was fine.
Me: Just fine? Is there anything we could do to make it easier for the next person we onboard?
Report: No, I don't think so.
Me: Oh, okay. Well I know Team Lead was looking into refactoring that code and updating the docs and she was looking for suggestions. If you're saying the component is good as it is, I might tell her that we should delay that until later this year.
Report: Well actually...
-----
Basically first I tried to relate to them a bit and share my experience. My hope is that if they are worried about looking dumb or incompetent in front of their peers, this defuses that
Second, I tried to ask something open ended. If they're just kind of on auto pilot, asking something that can't be answered with a yes/no answer can help shake them out of that.
Third, I put words in their mouth and just labeled them with an opinion they might or might not have. I don't love this one because it can feel a little manipulative, but I'm trying to get them to take a position and understand the consequences of not taking a position. It's kind of the equivalent of sending an email saying "I'm going to do X unless you tell me not to". At this point, either they agree with what you said and you can hold them to that or they have to give you an alternate opinion. Again, not my favorite tactic so I only use it on things that matter, but it works really well.
Another way of approaching that third attempt that feels a little less manipulative is "From my perspective it looks like XYZ. What do you think about that?"
So for example a conversation may go like this:
-----
Me: Hey, so you've been on project X for a month now. How are you feeling about it?
Report: It's good.
Me: I know this is the first time you're using Y technology. Are you finding the ramp up easy?
Report: Yeah. It's not too bad.
Me: That's great! I remember when I was working in that codebase it took me forever to understand Z component. What did you think of that?
Report: Oh, yeah. I worked in there, it was fine.
Me: Just fine? Is there anything we could do to make it easier for the next person we onboard?
Report: No, I don't think so.
Me: Oh, okay. Well I know Team Lead was looking into refactoring that code and updating the docs and she was looking for suggestions. If you're saying the component is good as it is, I might tell her that we should delay that until later this year.
Report: Well actually...
-----
Basically first I tried to relate to them a bit and share my experience. My hope is that if they are worried about looking dumb or incompetent in front of their peers, this defuses that
Second, I tried to ask something open ended. If they're just kind of on auto pilot, asking something that can't be answered with a yes/no answer can help shake them out of that.
Third, I put words in their mouth and just labeled them with an opinion they might or might not have. I don't love this one because it can feel a little manipulative, but I'm trying to get them to take a position and understand the consequences of not taking a position. It's kind of the equivalent of sending an email saying "I'm going to do X unless you tell me not to". At this point, either they agree with what you said and you can hold them to that or they have to give you an alternate opinion. Again, not my favorite tactic so I only use it on things that matter, but it works really well.
Another way of approaching that third attempt that feels a little less manipulative is "From my perspective it looks like XYZ. What do you think about that?"