Evidence-based decision making is becoming increasingly important in many diverse domains, including healthcare, environmental management, and government. This has raised the need for tools to aggregate evidence from multiple sources. For instance, in healthcare, much valuable evidence is in the form of the results from clinical trials that compare the relative merits of treatments. For this, in a previous paper [5], we have proposed a general language for encoding, capturing and synthesizing knowledge from clinical trials and a framework that allows the construction and evaluation of arguments from such knowledge. Now, in this paper, we consider a specific version of the general framework for aggregating qualitative information about trials, and undertake an evaluation of this qualitative framework by comparing the results we obtain with those that are published in the biomedical literature. Whilst the results from our qualitative system are inferior, we show that they do offer a quic...