This is one of my favorites from a previous employer. It requires a bit of background, so stick with me. I’m going to try and explain this is somewhat generic terms for those of you without a biology background. Let me know if this isn’t clear

I used to do computer-based genetic analysis. The lab used to depend on my team to help them create good, clean data for our product and research.
When processing a new batch of tissue, the lab did something called a “pilot” in which they sequenced a small amount of the DNA from that tissue to test the results of their processing. I then put this pilot through our computer programs to analyze how much if the information was “junk” and how much was viable and unique sequences. We used this information in the pilot to estimate the results when we did a full-scale run of that tissue.
So I get a phone call one day and it is Lisa, the head of our lab. The following conversation takes place.
Lisa: Hi, so we’ve got customer X coming in today, but I’ve just realized their pilot is only just now going through sequencing. They should be able to get you the data by 3m today, but the meeting is at 2. How quickly can you do your analysis?
Me: The processing time is usually about 2-3 hours, so the earliest I’d have information is about 5pm.
Lisa: Well that is too late, the customers are only stopping by for a quick meeting, so they’ll be gone shortly after 3.
Me: I’m sorry, but I can’t make the computers run faster than they do. I can drop everything and work on your data as soon as it shows up, but that is the best I can do.
Lisa: Hmmm, well could you tell me what you think the results of this pilot will be?
Me: You want me to predict the results of the test run?
Lisa: Yes.. if I had estimates, that would make the customer happy.
Me: I can’t predict the results because I have no idea if your processing was successful. A pilot is a test run, used to predict the results of the full run; I can’t predict the results of a test run because I haven’t seen the data.
Lisa: Well can’t you just give me an estimate.
Me: Explaining the concept of “test run” again.
Cycle repeated a few more times…
Me: Lisa, I’m not sure what you want me to do. Do you want me to go down to the lab, place the dish with the samples in it up to my forehead, and then use my psychic powers to determine how many of the samples are junk DNA? Because really, it sounds like that is what you are asking for.
Lisa: Well, ok maybe I was asking you for something impossible.