This exercise, to make an origami ball, was used to determine a representative time multiplier for a simple, well defined, familiar and unfamiliar fabrication task. In advance, students unfamiliar with origami estimated that it would take roughly 0-much more than 3 times longer to make the ball as did students with origami experience. On average they took about 3-4 times longer. However, in isolation they would have likely taken significantly longer than they had predicted ...when students familiar with the ball had completed their own ball, they helped the inexperienced students and thereby significantly lowered their time to complete the ball. For those unfamiliar with making the ball, the actual time to make the ball was 1X to over 10X higher than the time they estimated, centered around 3-4X (with high variability). For those familiar with origami, the actual time to make the ball was ~0.5-4X higher than their estimated time, with a mean around 1.5X (with much less variability). When estimating the time needed to complete a task, it is important to consider the task's familiarity, complexity, and how well it is defined (uncertainty). When developing a schedule, always add an appropriate multiplier when allocating the time needed to complete a task. Ball fabrication instructions Plots of estimated fabrication time Plots of actual fabrication time Plots of actual fabrication time/estimated fabrication time