- Aug 2018
Another way to use a classification system is to consider if there are other possible values that could be used for a given dimension.
Future direction: Identify additional sample values and examples in the literature or in situ to expand the options within each dimension.
For researchers looking for new avenues within human computation, a starting point would be to pick two dimensions and list all possible combinations of values.
Future direction: Apply two different human computation dimensions to imagine a new approach.
These properties formed three of our dimensions: motivation, human skill, and aggregation.
These dimensions were inductively revealed through a search of the human computation literature.
They contrast with properties that cut across human computational systems: quality control, process order and task-request cardinality.
A subtle distinction among human computation systems is the order in which these three roles are performed. We consider the computer to be active only when it is playing an active role in solving the problem, as opposed to simply aggregating results or acting as an information channel. Many permutations are possible.
3 roles in human computation — requester, worker and computer — can be ordered in 4 different ways:
C > W > R // W > R > C // C > W > R > C // R > W
The classification system we are presenting is based on six of the most salient distinguishing factors. These are summarized in Figure 3.
Classification dimensions: Motivation, Quality control, Aggregation, Human skill, Process order, Task-Request Cardinality
"... groups of individuals doing things collectively that seem intelligent.” 
Collective intelligence definition.
Per the authors, "collective intelligence is a superset of social computing and crowdsourcing, because both are defined in terms of social behavior."
Collective intelligence is differentiated from human computation because the latter doesn't require a group.
It is differentiated from crowdsourcing because it doesn't require a public crowd and it can happen without an open call.
Data mining can be defined broadly as: “the application of specific algorithms for extracting patterns from data.” 
Data mining definition
No human is involved in the extraction of data via a computer.
“... applications and services that facilitate collective action and social interaction online with rich exchange of multimedia information and evolution of aggregate knowledge...” 
Social computing definition
Humans perform a social role while communication is mediated by technology. The interaction between human social role and CMC is key here.
The intersection of crowdsourcing with human computation in Figure 1 represents applications that could reasonably be considered as replacements for either traditional human roles or computer roles.
Authors provide example of language translation which could be performed by a machine (when speed and cost matter) or via crowdsourcing (when quality matters)
“Crowdsourcing is the act of taking a job traditionally performed by a designated agent (usually an employee) and outsourcing it to an undefined, generally large group of people in the form of an open call.” [24
Labor process of worker replaced by public.
modern usage was inspired by von Ahn’s 2005 dissertation titled "Human Computation"  and the work leading to it. That thesis defines the term as: “...a paradigm for utilizing human processing power to solve problems that computers cannot yet solve.”
Human computation definition.
Problem solving by human reasoning and not a computer.
When classifying an artifact, we consider not what it aspires to be, but what it is in its present state.
Criterion for determining when/if the artifact is a product of human computation.
human computation does not encompass online discussions or creative projects where the initiative and flow of activity are directed primarily by the participants’ inspiration, as opposed to a predetermined plan designed to solve a computational problem.
What human computation is not.
The authors cite Wikipedia as not an example of human computation.
"Wikipedia was designed not to fill the place of a machine but as a collaborative writing project in place of the professional encyclopedia authors of yore."
Human computation is related to, but not synonymous with terms such as collective intelligence, crowdsourcing, and social computing, though all are important to understanding the landscape in which human computation is situated.
- social computing
- collective intelligence
- social coordination
- human computation
- data mining
n human computation, people act as computational components and perform the work that AI systemslack the skillstocomplete
Human computation definition.