Criterion;"Case 1: Tame problems that may appear wicked – managing ballast water as a vector";"Case 2: Problems that may be tame or wicked, depending on management goals – eradications on islands";"Case 3: Wicked problems incorrectly perceived as tame become more wicked – invasive forestry species";"Case 4: Disagreement over the nature of the problem ensures wickedness – invasive sport fishes" "1) You don’t understand the problem until you have developed a solution";"No. Although management plans aimed at every potential invasive species are impractical, a management approach that deals with all potential invaders simultaneously (e.g. vector control) becomes simple to define.";"Yes. Although the problem of eradicating a single species is easy to define, and has a clear solution, this would not guarantee ecosystem restoration. If the problem is more appropriately formulated as “Restore Island A to pre-invasion state” both the problems and potential solutions arguably become difficult to define a priori.";"Yes. The solutions proposed to address this problem have dealt with a particular aspect of the problem (e.g. provide timber, protect water resources or biodiversity, or create employment) which has led to unsatisfactory outcomes for stakeholders who were ignored initially.";"Yes. Many countries recognize invasive salmonids as a both problem and an asset, and hence have not developed a broadly accepted solution. In most countries, stakeholders have a diversity of views based on varying perspectives, values, politics, and financial resources. As a result, if deemed a problem, solutions may vary widely." "2) Wicked problems have no stopping rule";"No. A comprehensive risk assessment and management plan for all species transported in ballast water is impossible, as the potential species pool is unbounded. It is however possible to successfully manage the vector itself.";"No. The problem might be declared solved if a single species is eradicated, and new introductions can be prevented.";"Yes. Pines can never be eradicated, so their management can never be stopped. The question becomes one of whether the invasions can be brought to a level where they can be contained sustainably. This should be possible but, despite considerable control efforts, pines continue to spread.";"Yes. When management for any of the conflicting goals is the solution, there is never a point of ultimate success. Decision makers are often reluctant to identify a stopping rule given the diversity of stakeholder views." "3) Solutions to wicked problems are not right or wrong";"No. One could argue that the vector-management approach to ballast water invasions is appropriate, as it nullifies other drivers of wickedness in this case.";"No. A method that completely eradicates a single species can be called “correct”, although methods used to restore ecosystems may be subjectively assessed on their overall success.";"Yes. Pines are “conflict” species (simultaneously bringing benefits and doing harm), so it is necessary to make trade-offs, because it is both “right” to encourage benefits and “wrong” to tolerate harm.";"Yes. Managing against the spread of invasive trout and its impacts may be viewed as “right” by conservationists but are likely to be viewed simultaneously as “wrong” by anglers who utilize the resource." "4) Every solution to a wicked problem is a ‘one-shot operation’ that leads to new problems.";"No. The management of invasion risk by controlling the vector through effective regulations means that each potential species invasion is prevented by the same, repeatable method.";"Yes. Eradicating a species from an island will always depend on environmental context (geographic extent, logistical feasibility) for its success. Context dependency increases significantly with island size and ecosystem diversity. Removal of one species can lead to new problems.";"Yes. Pines were introduced to provide timber, but became invasive, leading to reduced water supplies and biodiversity. The solution was to initiate control operations, but these could not be sustained. This was “solved” by combining control with poverty-relief to create employment leading to a shift in emphasis to job creation at the expense of effective control.";"Yes. The historical, social and environmental context of each invasive trout population makes each solution have a wide range of potential unintended consequences." "5) Wicked problems have no given alternative solutions";"No. Whether attempting to prevent a single species or all species from successfully using the ballast water pathway to enter North American waters, the treatment of ballast water is the clear solution to minimize the risk of introduction.";"Yes. Some species can be eradicated from a defined geographic area using a small number of known methods. Ecosystem restoration has innumerable potential solutions based on the definition of restoration.";"Yes. We seek to maintain forestry production in conjunction with control, but this appears to be unattainable, and all alternative partial solutions remain contentious.";"Yes. There are at least three solutions – accept the invasion, eradicate, control. The latter two have many options, though many would be considered unacceptable by anglers." "6) Every wicked problem is essentially unique and novel";"No. Ballast water as a vector has several key traits that make standardized treatment solutions viable across many different shipping routes.";"Yes. The solution for eradicating one species on an island is likely to work on another island with the same species, but the implications of the eradication for ecosystem rehabilitation will be case-specific.";"Yes. The problem of invasive pines in the Cape Floristic Region is embedded in a dynamic social-ecological context, where numerous factors interact, resulting in a unique situation for each stand of invasive pines.";"Yes. Each salmonid population will have unique logistical constraints surrounding its management, as well as an associated group of stakeholders, who add individuality to the nature of the problem and its potential solutions."