The visualisation of data has become ubiquitous. Visualisations are used to represent data in a way that is easy to understand and useful in our lives. Each data visualisation needs to be suitable to extract the correct information to complete a task and make an informed decision while minimising the impact of biases. To achieve this, the ability to create and read visualisations has become as important as the ability to read and write. Therefore, the Information Visualisation community is applying more attention to literacy and decision making in data visualisations. Until recently, researchers lacked valid and reliable test instruments to measure the literacy of users or the taxonomy to detect biased judgement in data visualisations. A literature review showed there is relatively little research on data visualisations for different user data literacy levels in authentic settings and a lack of studies that provide evidence for the presence of cognitive biases in data visualisations. This exploratory research study was undertaken to develop a method to assess perceived usefulness and confidence in reporting dashboards within higher education by adapting existing research instruments. A survey was designed to test perceived usefulness, perceived skill and 24 multiple-choice test items covering six data visualisations based on eight tasks. The study was sent to 157 potential participants, with a response rate of 20.38%. The results showed data visualisations are useful, but the purpose of some data visualisations is not always understood. Also, we showed there is a consensus that respondents perceive their data visualisation literacy is higher than they believe their peers to be. However, the higher their overconfidence, the lower their actual data visualisation literacy score. Finally, we discuss the benefits, limitations and possible future research areas.