  Hyperdimensional computing (HDC) has become popular for light-weight and
energy-efficient machine learning, suitable for wearable Internet-of-Things
(IoT) devices and near-sensor or on-device processing. HDC is computationally
less complex than traditional deep learning algorithms and achieves moderate to
good classification performance. This article proposes to extend the training
procedure in HDC by taking into account not only wrongly classified samples,
but also samples that are correctly classified by the HDC model but with low
confidence. As such, a confidence threshold is introduced that can be tuned for
each dataset to achieve the best classification accuracy. The proposed training
procedure is tested on UCIHAR, CTG, ISOLET and HAND dataset for which the
performance consistently improves compared to the baseline across a range of
confidence threshold values. The extended training procedure also results in a
shift towards higher confidence values of the correctly classified samples
making the classifier not only more accurate but also more confident about its
predictions.
