I love an old-school to-do list. It's a piece of scrap paper that I keep right next to my keyboard. I write things in pencil so I can easily change them, and I take great satisfaction when I complete something and can cross it off with a dark, thick line. (No little check marks for me.)

Sometimes I even have two lists going at once. There's my short-term to-do list and occasionally a list of long-range items. I keep them separate so I don't get frustrated because it takes so long to get them accomplished. When my short-term list gets too scribbly, I start a new one and just copy over anything left. It sounds pretty lax, but I get a lot accomplished and it's relatively fulfilling.

I know people (including myself, back in my more serious in-the-office days) who have more formal to-do lists. They are color-coded and time-stamped with items having exact deadlines and little wiggle room.

Researchers say there's a downside to that traditional time-management planning: Our workdays rarely go without interruptions and that kind of planning only works when no one throw a wrench into your day. One unannounced meeting or other interruption and all those carefully laid planned get thrown out of whack.

Studying how people plan

hourly to-do list If every minute of your day is planned, interruptions can affect your productivity and job satisfaction. (Photo: David Mail/Shutterstock)

Researchers from universities in the United States, Canada and the United Kingdom spent two weeks tracking 187 employees to study their planning styles and how effective they were. They identified people who use traditional time management versus those who are contingent planners, meaning they assume they'll have disruptions and are able to be flexible to deal with changes in the daily routine.

Researchers measured the number of interruptions workers had every day and tracked how engaged and focused employees felt, in addition to how well they thought they were able to meet their job responsibilities.

They found strong correlations between the type of planning that employees used (traditional time management or contingency) and the strength of their job satisfaction as well as their work output.

"People who used traditional time management were more engaged and productive when they had few interruptions. People who used contingent planning were more engaged and productive no matter whether they were interrupted or not," according to UCLA Anderson Review.

And on days when interruptions were particularly high, people who relied on traditional time management techniques really suffered at productivity and job engagement. That happened as frequently as 20 percent of the time.

So the more you're able to go with the flow while dealing with what interruptions are thrown your way at work, the more likely you are to get more done and enjoy your job.

The researchers, who published their work in the Journal of Applied Psychology, suggest preparing for each workday by considering whether you might be interrupted and if so, how often and for how long. If you expect zero or few interruptions, set an ambitious to-do list that prioritizes your tasks. If you expect many interruptions, set a more realistic to-do list that takes into account all the other things that might need addressing that day.

And maybe use pencil.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

Why you need a much more chill to-do list
You know you'll be interrupted at work, so learn to plan for it.