I have this colleague who is somewhat sloppy with their work e.g. not doing proper experiments, not ensuring the setups are correct, wrong citations, etc.

Now, we're all humans and we do mistakes; I appreciate that. However, if it's just pure laziness and the don't-care-attitude... that I've a problem.

Would you consider this lazy-don't-care-attitude unethical? Or, at least problematic to you in a huge way? How do you handle them?

I'd say if it affects your work or general safety of others, then you need to say something either to them or your supervisor.

If it doesn't affect you and the only person they are harming are themselves, then I'd mind my own business. Unfortunately, academia is a world in which the whistle blower as well as guilty party may be quietly moved on. Their own results will hopefully not stand up to scrutiny at viva or paper publication.

Unfortunately, sometimes people do get away with it due to insufficient scrutiny and I know of one post-doc who deliberately left out unfavourable results to present a rosier picture of his data. One of my colleagues knew what he was doing, however, said nothing as he did not want to be seen to 'rock the boat' in a way that would affect future job references.

Ian (Mackem_Beefy)

Actually, it can be quite dangerous if you share equipment with someone who is not meticulous.
When the equipment is spoilt, it may take some time to be repaired. Worst still, your experimental data could be questionable or your thesis deadline can be affected.

To be proactive, it may be good to understand this colleague's situation.
Try helping him to visualize hope or success...

If this is affecting the opening poster, he does need to do something. Perhaps asking the colleague if everything is okay (i.e being proactive) before taking it further, to see if there is a problem (be a mate) may be the best approach to begin with. It may be personal problems or insufficient training (which can happen) are affecting them.

My earlier post is the perspective of someone who's been through the mill. Poor practice shouldn't be allowed, however, the person pointing out the bad practice can be seen to be 'rocking the boat'. I've seen plenty instances and also been in the situation where pointe dout a problem (second post-doc not at PhD Uni.) and it was strongly implied I should 'shut up'.

Ian (Mackem_Beefy)