Estimating is Hard

I'm coming up on the end of my first iteration at 8th Light where I was asked to estimate how long each of my stories was going to take. For the three stories that make up the majority of converting my rack Tic-Tac-Toe from a multi-page vanilla HTML/CSS app, to a SPA (Single Page App) that uses AJAX to communicate with the server I came up with a total of about 11 points. Given that at 8th Light we want to be nominally doing about 9 points per week that meant that I estimated it would take me just a touch over one iteration to complete that transformation. But looking at it right now, I don't think I'm on track to meet that goal.

Estimating is acknowledged to be hard. The advice from The Pragmatic Programmer acknowledges that and says that basically the only way to get better at it is to try and estimate things and then track how (in)accurate your estimates are. Beyond that general acknowledgement though, I think I have some personal habits/quirks that make my estimates less than good.

First, I have a tendency to want to seem like I know what I'm doing, even when I don't. This is obviously problematic for estimation since in it's simplest form it might make me underestimate how long I think something will take so I look more proficient. There's a more insidious way that this attitude causes me problems though. It means I have a tendency not to ask questions, and I probably tend to bang my head against things that aren't working for too long before I ask for help.

The second problem I have is reading things and ensuring I actually am comprehending them. This is sort of related to the first problem since I think it comes from a similar place. But at this point it's more of a mental habit than an explicit choice. For instance, even though I didn't have a short time limit to figure out my estimates, I still did them fairly quickly and without really having a clear picture of what work I would have to do for each story. As soon as I started trying to implement the stories, I realized this.

The Takeaway

I need a more systematic approach to the way I come up with estimates. First off, I'm going to go re-read the article on it from The Pragmatic Programmer. As I recall it has some excellent advice that I don't remember half well enough. Second, I think I'm going to try to partially adopt a strategy that my co-mentor Zach suggested when I was reviewing a code-base's "viability for extension." His advice was to walk through the code while considering what it would take to make some sort of reasonable change.

This is quite nebulous for a large code-base, since I first have to decide what "a reasonable change" might be. But as a tool for reifying the goals that I'm trying to estimate it should work very nicely. Basically, all that this means is that I will actually seriously try to think through what I would do to implement the story I'm trying to estimate instead of just throwing a number out from my gut feeling.

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