The use of behavioural change systems in providing interventions for people is common in this present era of information technology. Many people depend on these systems for many reasons like safe driving, healthy food consumption, energy conservation, etc. Some of these systems have been successful in making people change positively while a larger percentage have not been successful due to many issues that were not addressed during the development of such systems. One of them is psychological reactance, a motivational state that is aroused when a person’s freedom is threatened or eliminated. It has major focus restoring any freedom that has been threatened. This forms the motivation for this work and it starts with a brief study of the theory of psychological reactance with a new view of accessing it from perceived usability perspective. To study reactance in people, a survey was conducted. It focussed on accessing reactance through attitudes to forced compliance in a persuasive website in the context of meal-planning. Results from this study showed that participants with high freedom text had better attitude to the website in terms of anger and perceived usability than participants with low-freedom text. This work confirmed the social agency proposition that the presence of social cues in a multimedia message can stimulate the social interaction pattern in people’s learning. Once this social interaction pattern is initiated, there is a high possibility for pupils to act as if they are interacting with another individual. Therefore, to some degree, social convention of human-to-human interaction sets in as participants with high freedom message had a lower anger score than participants with high freedom plus social message.

The freedom concept has been an important one, to daily engagement in activities and everything that becomes so close to people. One of them is computing systems that we use every day and they serve several purposes in moulding human lives. An important aspect of this is behaviour change as many have been successful while others have failed because they are too restrictive for use. However, the presence of freedom does not guarantee the success of many systems. Therefore, this work focuses on how reactance can still be experienced in a persuasive website that ensures freedom and non-forced compliance. Specifically, the work studied anger, compliance and perceived usability of a persuasive website that was developed to provide intervention for users in the area of healthy meal planning through manipulation of freedom levels. Results indicated that participants exposed to high freedom text had lower anger, higher perceived usability and higher compliance than participants exposed to low freedom text and social high freedom message. This led to the conclusion that users’ freedom feeling during a persuasive attempt can be boosted with the inclusion of high freedom message design and that the integration of social agents for persuasion enhancement must be done with great care.Keywords: Psychological Reactance, Freedom, Behaviour change, Social Influence, compliance, persuasion, computing devices

A locally developed autogenous single screw extruder was used to investigate the process for screw extrusion of the flour and starch of cassava, in a bid to find alternate uses for the commodity. The experiment was conducted with a factorial design and completely randomized.  Analysis of Variance and Tukey Honestly Significant Difference methods were utilized as follow up test  to check the result of extrusion variables: feed moisture (25, 30, 40%) and extruder temperature built up by varying the duration of sampling (2, 10, 18, 24, 30 minutes) on some product quality attributes and system parameters. The product quality attributes considered include water absorption index (WAI) and water solubility index (WSI), product moisture (PQ_MC), transverse expansion (ExR), cold and hot paste viscosities (CPV and HPV), Melt viscosity (MV) and strength properties of extrudates (CP) while the system parameters are product temperature (PT), mean residence time (MRT), and specific energy input (SME). All system parameters PT, MRT and SME varied directly with duration of operation. Also, PQ_MC, CP, WAI, WSI, MV, CPV and HPV varied reciprocally whereas ExR, and MV varied directly with duration of operation. The extrudates’ water loss is directly proportional with ExR. It was observed that extruded cassava starch was less stable than cassava flour extrudates. Moreover, the specific end uses to which the extruded products can be put were identified. All the treatments and their interactions are highly significant (P ≤ 0.001).