We could also add a fourth image to the series illustrating both poor accuracy and poor precision. Consider what that situation would look like. In a few sentences, using the analogy, describe how the target would look, and suggest a possible reason for this case.

O A B C In A, the measurements shown are centred around the target but there is significant scatter. For a result such as this, one could guess that bow is well-sighted, but wind or other factors cause random variation in the arrows. This might be typical of a situation where a measuring instrument is well-calibrated and there are minimal "systemic" errors, but random "noise" significantly influences the measurements. The results can be said to be accurate but they are also imprecise. In B meanwhile, the measurements are tightly grouped but consistently off-target. One could guess that the bow is poorly-sighted, but wind conditions still allow a tight grouping of arrows. In this case perhaps the measuring instrument is poorly calibrated, or maybe the results are influenced by other consistent systemic errors. For example, the investigator may simply be reading the tool incorrectly (e.g. parallax errors if looking at a measuring scale at an angle instead of directly), or inadvertently affect the reading (e.g. slightly altering a temperature reading by holding the the thermometer directly). However, the tight grouping of the results shows high precision; that is, the effects of random noise sources appear less influential in these result. In C, the results shown illustrate both accuracy (i.e. minimal systemic errors) and precision (i.e. low noise); the bow is well-sighted, and the wind conditions (in this analogy) are light, so the arrows land on target and are tightly grouped). 1. Pre-lab question: We could also add a fourth image to the series illustrating both poor accuracy and poor precision. Consider