1. Anyone can solve common problems The world is packed with common problems awaiting for solutions - global warming, urban air pollution, contaminants in drinking water and food to name a few. Many people would be willing to make an effort in solving these problems but so far have been lacking practical means to contribute. Now a tool exists to address this need. Opasnet is an open workspace in the internet where anyone can bring in their knowledge and values to inform decisions and actions on common problems. http://en.opasnet.org

2. What is Opasnet? –Opasnet is an open web-workspace (en.opasnet.org) that is used for collecting, synthesizing and communicating knowledge and values for the purpose of guiding societal decision making..opasnet.org –Like Wikipedia, it builds on the power of mass collaboration. –Opasnet is available to anyone. You can initiate new assessments, contribute to existing assessments, or just read about existing assessments on practical problems. The basic idea of open assessment is to collect information that is needed in a decision-making process. The information is organised as an assessment that predicts the impacts of different decision options on some outcomes of interest. Information is organised to the level of detail that is necessary to achieve the objective of informing decision-makers. An assessment is typically a quantitative model about relevant issues causally affected by the decision and affecting the outcomes. Decisions, outcomes, and other issues are modelled as separate parts of an assessment, called variables. In practice, assessments and variables are web pages in Opasnet, a web- workspace dedicated for making these assessments. Such a web page contains all information (text, numerical values, and software code) needed to describe and actually run that part of an assessment model.assessmentvariables How does Opasnet work? –Opasnet consists of a wiki-type web system, a database for storing large amounts of quantitative information, and modelling software for making quantitative decision models. –Opasnet relies on systematic information structure, which supports effective knowledge collection, synthesis and communication. –Mass collaboration is made possible by splitting information into chunk-size pieces. This way a person with some small valuable piece of knowledge is able to contribute, and the small pieces of knowledge eventually grow into a large body of information. –Openness is a means to guarantee the integrity and quality of information, because all contributions are openly subject to scientific criticism. –Formal argumentation, taking place within the Opasnet itself, is used for structuring critique and resolving disputes about the content.

3. A screenshot of an assessment page in Opasnet An example of formal argumentation in Opasnet

4. Basic concepts These web pages are also called information objects, because they are the standard way of handling information as chunk-sized pieces in open assessments. Each object (or page) contains information about a particular issue. Each page also has the same, universal structure: a research question (what is the issue?), rationale (what do we know about the issue?), and result (what is our current best answer to the research question?). The descriptions of these issues are built on a web page, and anyone can participate in reading or writing just as in Wikipedia. Notably, the outcome is owned by everyone and therefore the original authors or assessors do not possess any copyrights or rights to prevent further editing.information objectsuniversal structureWikipedia The structure of information objects can be likened to a fractal: an object with a research question may contain sub-questions that could be treated as separate objects themselves, and a discussion about a topic could be divided into several smaller discussions about sub-topics. For example, there may be a variable called Population of Europe with the result indexed by country. Instead, this information could have been divided into several smaller population variables, one for each country - for example in the form of a variable called Population of Finland. How information is divided or aggregated into variables is a matter of taste and practicability and there are no objective rules. Instead, the rules only state that if there are two overlapping variables, the information in them must be coherent. In theory, there is no limit to how detailed the scope of an information object can be.fractal Population of EuropeindexedPopulation of Finland Trialogue is the term used to define Wikipedia-like contributions. The trialogue concept emphasises that, in addition to having a dialogue or discussion, a major part of the communication and learning between the individuals in a group happens via information objects, in this case Opasnet pages. In other words, people not only talk or read about a topic but actually contribute to an information object that represents the shared understanding of the group. Wikipedia is a famous example of trialogical approach although the wikipedists do not use this word.TrialoguegroupWikipediatrialogical approach Groups are crucial in open assessment because all research questions are (implicitly) transformed into questions with the format: "What can we as a group know about issue X?" The group considering a particular issue may be explicitly described, but it may also be implicit. In the latter case, it typically means anyone who wants to participate, or alternatively, the whole of humanity.Groups The use purpose of information is crucial because it is the fuel of assessments. Nothing is done just for fun (although that is a valid motivation as well) but because the information is needed for some practical, explicit use. Of course, other assessments are also done to inform decisions, but open assessments are continuously being evaluated against the use purpose; this is done to guide the assessment work, and the assessment is finished as soon as the use purpose is fulfilled.

5. Basic procedures Inference rules are used to decide what to believe. The rules are summarised as follows:Inference rules Anyone can promote a statement about anything (promote = claim that the statement is true).statement A promoted statement is considered valid unless it is invalidated (i.e., convincingly shown not to be true). The validity of a statement is always conditional to a particular group (which is or is not convinced). A statement always has a field in which it can be applied. By default, a scientific statement applies in the whole universe and a moral statement applies within a group that considers it valid. Two moral statements by a single group may be conflicting only if the fields of application do not overlap. There may be uncertainty about whether a statement is true (or whether it should be true, in case of moral statements). This can be quantitatively measured with subjective probabilities.uncertaintysubjective probabilities There can be other rules than these inference rules for deciding what a group should believe. Rules are also statements and they are validated or invalidated just like any statements. If two people within a group promote conflicting statements, the a priori belief is that each statement is equally likely to be true. A priori beliefs are updated into a posteriori beliefs based on observations (in case of scientific statements) or opinions (in case of moral statements) and open criticism that is based on shared rules. In practice, this means the use of scientific method. Opinions of each person are given equal weight.open criticism Tiers of open assessment process describe typical phases of work when an open assessment is performed. Three tiers are recognised as follows:Tiers of open assessment process Tier I: Definition of the use purpose and scope of an assessment. Tier II: Definition of the decision criteria. Tier III: Information production. It is noteworthy that the three tiers closely resemble the first three phases of integrated environmental health impact assessment, but the fourth phase (appraisal) is not a separate tier in open assessment. Instead, appraisal and information use happens at all tiers as a continuous and iterative process. In addition, the tiers have some similarities also to the approach developed by the BRAFO project. BRAFO It is clear that within a self-organised group, not all people agree on all scientific or moral statements. The good news is that it is neither expected nor hoped for. There are strong but simple rules to resolve disputes, namely rules of structured discussions. In straightforward cases, discussions can be informal, but with more complicated or heated situations, the discussion rules are followed:discussions Each discussion has one or more statements as a starting point. The validity of the statements is the topic of the discussion. A statement is valid unless it is attacked with a valid argument.argument Statements can be defended or attacked with arguments, which are themselves treated as statements of smaller discussions. Thus, a hierarchical structure of defending and attacking arguments is created. When the discussion is resolved, the content of all valid statements is incorporated into the information object. All resolutions are temporary, and anyone can reopen a discussion. Actually, a resolution means nothing more than a situation where the currently valid statements are included in the content of the relevant information object.

6. Technical functionalities supporting open assessment Opasnet is the web-workspace for making open assessments. The user interface is a wiki and it is in many respects similar to Wikipedia, although it also has enhanced functionalities for making assessments. One of the key ideas is that all work needed in an assessment can be performed using this single interface. Everything required to undertake and participate in an assessmeent is therefore provided, whether it be information collection, numerical modelling, discussions, statistical analyses on original data, publishing original research results, peer review, organising and distributing tasks within a group, or dissemination of results to decision-makers.peer review In practice, Opasnet is an overall name for many other functionalities than the wiki, but because the wiki is the interface for users, Opasnet is often used as a synonym for the Opasnet wiki. Other major functionalities exist as well, aas outlined below. The main article about this topic is Opasnet structure.Opasnet structure Most variables have numerical values as their results. Often these are uncertain and they are expressed as probability distributions. A web page is an impractical place to store and handle this kind of information. For this purpose, a database called Opasnet Base is used. This provides a very flexible storage platform, and almost any results that can be expressed as two-dimensional tables can be stored in Opasnet Base. Results of a variable can be retrieved from the respective Opasnet page. Opasnet can be used to upload new results into the database. Further, if one variable (B) is causally dependent on variable (A), the result of A can be automatically retrieved from Opasnet Base and used in a formula for calculating B.resultsOpasnet Baseformula Because Opasnet Base contains samples of distributions of variables, it is actually a very large Bayesian belief network, which can be used for assessment-level analyses and conditioning and optimising different decision options. In addition to finding optimal decision options, Opasnet Base can be used to assess the value of further information for a particular decision. This statistical method is called Value of information.Bayesian belief networkValue of information Opasnet contains modelling functionalities for numerical models. It is an object- oriented functionality based on the R statistical software and the results in Opasnet Base. Each information object (typically a variable) contains a formula which has detailed instructions about how its result should be computed, often based on results of upstream variables in a model.R

7. Meta level functionalities In addition to work and discussions about the actual topics related to real-world decision-making, there is also a meta level in Opasnet. Meta level means that there are discussions and work about the contents of Opasnet. The most obvious expression of this are the rating bars in the top right corner of many Opasnet pages. Peer rating means that users are requested to evaluate the scientific quality and usefulness of that page on a scale from 0 to 100. This information can then be used by the assessors to evaluate which parts of an assessment require more work, or by readers who want to know whether the presented estimates are reliable for their own purpose.rating barsPeer rating The users are also allowed to make peer reviews of pages. These are similar to peer reviews in scientific journals, with written evaluations of the scientific quality of content. Another form of written evaluation are acknowledgements, which are a description about who has contributed what to the page, and what fraction of the merit should be given to which contributor.peer reviews Estimates of scientific quality, peer reviews and acknowledgements can be used systematically to calculate how much each contributor has done in Opasnet, though these practices are not yet well developed: contribution scores are so far the only systematic method even roughly to estimate contributions quantitatively.contribution scores Respect theory is a method for estimating the value of freely usable information objects to a group. This method is under development, and hopefully it will provide practical guidance for distributing merit among contributors in Opasnet.Respect theory

8. Why does open assessment work? Many people are (initially at least) sceptical about the effectiveness of open assessment. In part, this is because ther approach is new and has not yet been widely applied and validated. Most examples of its use are for demonstration purposes. A number of reasons can nevertheless be advanced, supporting its use: In all assessments, there is a lack of resources, and this limits the quality of the outcome. With important (and controversial) topics, opening up an assessment to anyone will bring new resources to the assessment in the form of interested volunteers. The rules of open assessment make it feasible to organise the increased amount of new data (which may at some points be of low quality) into high-quality syntheses within the limits of new resources. Participants are relaxed with the idea of freely sharing important information - a prerequisite of an effective open assessment - because open assessments are motivated by the shared hope for societal improvements and not by monetary profit. This is unlike in many other areas where information monopolies and copyrights are promoted as means to gain competitive advantage in a market, but as a side effect result in information barriers. Problems due to too narrow initial scoping of the issue are reduced by having with more eyes look at the topic throughout the assessment process. It becomes easy systematically to apply the basic principles of the scientific method, namely rationale, observations and, especially, open criticism. Any information organised for any previous assessment is readily available for a new assessment on an analogous topic. The work time for data collection and the calendar time from data collection to utilisation are also reduced, thus increasing efficiency. All information is organised in a standard format which makes it possible to develop powerful standardised methods for data mining and manipulation and consistency checks. It is technically easy to prevent malevolent attacks against the content of an assessment (on a topic page in Opasnet wiki) without restricting the discussion about, or improvement of, the content (on a related discussion page); the resolutions from the discussions are simply updated to the actual content on the topic page by a trusted moderator. These points support the contention that open assessment (or approaches adopting similar principles) will take over a major part of information production motivated by societal needs and improvement of societal decision-making. The strength of this argument is already being shown by social interaction initiatives, such as Wikipedia and Facebook, However, an economic rationale also exists: open assessment is cheaper to perform and easier to utilise, and can produce higher quality outputs than current alternative methods to produce societally important information. www.thl.fiwww.thl.fi www.opasnet.org jouni.tuomisto[at]thl.fiwww.opasnet.orgjouni.tuomisto[at]thl.fi

9. Get involved with Opasnet! Go see Opasnet at en.opasnet.org and find out how to participate by:en.opasnet.org Reading Opasnet content Commenting Opasnet content Participating in polls Editing and creating Opasnet content Providing data to the Opasnet base Peer-reviewing Opasnet content Moderating parts of Opasnet You can also check out and contribute to the on- going assessments on e.g.: Impacts of emission trading on city-level Impacts of heating in small municipalities Climate change, air quality and housing Costs and benefits of composite traffic Benefits and risks of eating fish