Duncan Hedderley

Methodological issues in conjoint analysis: a case study

To help further our understanding of how keymethodological issues in conjoint analysis influence outcomes, a choice‐based conjoint study measuring consumer preferences for pre‐packed apple selection packs was conducted. The role of stimuli presentation format was considered by comparing the performance of physical prototype stimuli and realistic pictorial representations. This indicated no substantial differences in the choice decisions made using the two presentation formats and suggested that photographic images may be used instead of prototype stimuli. A second issue pertained to the need for training and warm‐up exercises prior to the actual conjoint choice task. While this indicated some differences in choice strategies, a significant improvement in internal validity of choice decisions made with and without training was not achieved. One possible explanation for this finding may be that respondents made choices between apple products, a product category for which decision strategies are likely to be stable and well‐developed.

Non conventional technologies and impact on consumer behavior.

Abstract Consumers are becoming more conscious about the potentially negative impact of food processing on human health and the environment. In particular, there is increased public concern about the application of emerging technologies such as genetic modification to food production, particularly with respect to consumer perceptions of potential for negative impact of genetically modified organisms on ecology. However, less is understood about consumer acceptance of potentially controversial technologies where such technological innovation replaces traditional manufacturing methods, which themselves have the potential for environmental harm. In the present study, consumer acceptance of a genetically modified product was examined. In this research, the process of genetic modification had the potential for reducing the environmental impact caused by the alternative, traditional method of production. The analysis took account of the effects of other factors such as reduced price and brand in consumer decision making, as well as the provision of information about manufacturing process. The product investigated was vegetable oil. One hundred and sixty five consumers evaluated the relative importance of different combinations of manufacturing process (traditional process, versus genetic modification) as well as the commercial brand (familiar versus unknown), price (low v ersus high) and label image (sunflower versus an image of a green globe indicating environmental friendliness), on purchase intentions. The data were analysed using conjoint and cluster analyses. Three clusters of consumers were identified. The first cluster (11% of the sample) based the purchase intention decisions on the label the image. The second one (25% of the sample) preferred environmentally friendly oil, highly priced and branded as Mazola. The third cluster (19% of the sample) considered mainly information about manufacturing process as of importance to their decision about purchases. In particular, these consumers preferred products associated with information about “environmentally friendly processing methods”. The results are compared with a similar sample of British respondents, and the implications of cross-cultural differences discussed.

Invasion by a perennial herb increases decomposition rate and alters nutrient availability in warm temperate lowland forest remnants

We determined the impact of the invasive herb, Tradescantia fluminensis Vell., on litter decomposition and nutrient availability in a remnant of New Zealand lowland podocarp–broadleaf forest. Using litter bags, we found that litter beneath mats of Tradescantia decomposed at almost twice the rate of litter placed outside the mat. Values of k (decomposition quotient) were 9.44±0.42 yrs for litter placed beneath Tradescantia and 5.42±0.42 yrs for litter placed in native, non-Tradescantia plots. The impact of Tradescantia on decomposition was evident through the smaller forest floor mass in Tradescantia plots (2.65±1.05 t ha−1) compared with non-Tradescantia plots (5.05±1.05 t ha−1), despite similar quantities of annual leaf litterfall into Tradescantia plots (6.85±0.85 t ha−1 yr−1) and non-Tradescantia plots (7.45±1.05 t ha−1 yr−1). Moreover, there was increased plant nitrate available, as captured on resin bags, in Tradescantia plots (25.77 ± 8.32 cmol(−)/kg resin) compared with non-Tradescantia plots (9.55±3.72 cmol(−)/kg resin). Finally, the annual nutrient uptake by Tradescantia represented a large proportion of nutrients in litterfall (41% N, 61% P, 23% Ca, 46% Mg and 83% K), exceeded the nutrient content of the forest floor (except Ca), but was a small proportion of the topsoil nutrient pools. Taken together, our results show that Tradescantia increases litter decomposition and alters nutrient availability, effects that could influence the long-term viability of the majority of podocarp–broadleaf forest remnants affected with Tradescantia in New Zealand. These impacts are likely mostly due to Tradescantias vegetation structure (i.e., tall, dense mats) and associated microclimate, compared with native ground covers.

Pollination studies of four New Zealand terrestrial orchids and the implication for their conservation

Abstract The New Zealand orchid flora comprises 25 genera and over 100 species. Most of the species are terrestrial and are found throughout the country. Terrestrial orchids are the most threatened group within the family. We studied the pollination ecology of four terrestrial orchids: Gastrodia cunninghamii, Thelymitra longifolia, Pterostylis alobula, and P. patens. Reproduction of these orchids relies on contrasting reproductive strategies. Thelymitra longifolia is predominantly self‐pollinated, whereas both Pterostylis species are cross‐pollinated and have an absolute dependence on pollinators. Hand‐pollination treatments showed T. longifolia, P. alobula, and P. patens to be self‐compatible. Results for G. cunninghamii were unclear and need further study. Insect flower visitation is uncommon in these species and was observed only in G. cunninghamii and P. alobula. Aphids were usually found inside the flowers of G. cunninghamii, but the role they may have as pollinators is undetermined. In P. alobula, male fungus gnats of Zygomyia (Mycetophilidae: Diptera) were considered pollinators. Hypotheses on the attraction system(s) used by these greenhood orchids are discussed. These two species are more likely to be affected by disruption of the plant‐pollinator mutualism because of the specialist nature of the plant‐pollinator interaction.

Plant functional groups in a heterogeneous environment

Abstract Species membership of plant functional groups and the relationship to soil variables were studied in two paddocks with long‐term differentiated management in New Zealand hill country. The microrelief of the paddocks contained three slope classes (low, medium, and high) with contrasting soil variables. Soil variables (unsaturated hydraulic conductivity, bulk density, volumetric soil moisture, total soil porosity, field volumetric soil moisture, soil compression, soil rebound, and air permeability), botanical composition and herbage mass accumulation were determined. Analysis of variance, cluster analysis, simple correlation analysis and canonical variate analysis were performed on the data. Seven functional plant groups were determined. High fertility grasses and Lolium perenne were strongly affected by changes in the level of soil variables. Low fertility species appeared to be affected indirectly by soil variables, as they were poor competitors when availability of soil resources was high. Some species (e.g., Agrostis capillaris) were indifferent to changes in the levels of available resources due to soil characteristics. Species and functional groups colonised the evaluated sites according to the soil resources. Species and functional groups were shown to have the capability to respond positively to soil resources, adjusting their growth according to the varying circumstances. The relationship between plant functional groups and field condition, a grazing management concept that measures the deviation from some ideal ecological state, was also examined. Results suggested that field condition and plant functional groups are complementary concepts in grassland dynamic analyses.

Software selection for the management and prevention of RSI in a diverse user community

Abstract This project involved the evaluation and selection of break reminder software for the management and prevention of Repetitive Strain Injury (RSI) in a university environment with a diverse user community. A feature analysis was undertaken initially to evaluate available software products on both user-centred and technical factors. As a result, three products were selected for detailed evaluation, which involved 24 subjects each using three pieces of software for a week. During this phase data was collected through interviews and questionnaires. The results show that two products scored equally well. This suggests that if software is to meet the needs of the user, some degree of choice is necessary. Relevance to industry: Musculoskeletal disorders caused by computer use continue to be a problem despite the introduction of strategies developed to combat it. Software monitoring tools for the management and prevention of RSI represent a tool in the armoury. There are now a plethora of such tools on the market. This paper describes a method for the evaluation and selection of such a tool.

A Behavioural Analysis of Sponsorship

Abstract Managers’ increasing use of sponsorship has not been parallelled by a growth in either their knowledge of evaluation methods or the sophistication of those they employ. Studies documenting management practice have revealed widespread use of informal sponsorship feedback measures and, where more formal measures are used, these relate only indirectly to sponsorship objectives. Given that most marketing actions are undertaken to change, modify or reinforce consumer’ behaviour, it is logical to examine whether sponsorship has any behavioural consequences. This paper outlines a choice modelling experiment designed to investigate how sponsorship affected consumers’ choice behaviour for two products: milk and bank investments. In both categories, sponsorship had a strong influence on the behaviour of a small group of consumers. However, overall, its influence was slight compared to the other attributes examined, and depended heavily on the cause promoted.

Evaluating the Behavioural Impact of the Australian and New Zealand Genetically Modified Food Labelling Provisions

Abstract This paper presents the results of a choice experiment that encompassed the labelling options outlined in the Australian and New Zealand governments recently finalized mandatory labelling system for genetically modified foods (GMFs) and foods that contain genetically modified ingredients. The labelling scheme is to be implemented across both countries from December 2001 onwards. Results suggest difficulties ahead for manufacturers and growers of GM labelled product if there is an ample supply of GM-free labelled alternatives. It is also likely that manufacturers and growers of GM-free product will realize greater levels of demand over non-labelled and GM product even when these alternatives are substantially cheaper.