  Science students must deal with the errors inherent to all physical
measurements and be conscious of the need to expressvthem as a best estimate
and a range of uncertainty. Errors are routinely classified as statistical or
systematic. Although statistical errors are usually dealt with in the first
years of science studies, the typical approaches are based on manually
performing repetitive observations. Our work proposes a set of laboratory
experiments to teach error and uncertainties based on data recorded with the
sensors available in many mobile devices. The main aspects addressed are the
physical meaning of the mean value and standard deviation, and the
interpretation of histograms and distributions. The normality of the
fluctuations is analyzed qualitatively comparing histograms with normal curves
and quantitatively comparing the number of observations in intervals to the
number expected according to a normal distribution and also performing a
Chi-squared test. We show that the distribution usually follows a normal
distribution, however, when the sensor is placed on top of a loudspeaker
playing a pure tone significant differences with a normal distribution are
observed. As applications to every day situations we discuss the intensity of
the fluctuations in different situations, such as placing the device on a table
or holding it with the hands in different ways. Other activities are focused on
the smoothness of a road quantified in terms of the fluctuations registered by
the accelerometer. The present proposal contributes to gaining a deep insight
into modern technologies and statistical errors and, finally, motivating and
encouraging engineering and science students.
