Abstract: Embodiments of the invention utilize a feature-extraction approach and/or a matching approach in combination with a nonparametric approach to estimate the proportion of documents in each of multiple labeled categories with high accuracy. The feature-extraction approach automatically generates continuously valued text features optimized for estimating the category proportions, and the matching approach constructs a matched set that closely resembles a data set that is unobserved based on an observed set, thereby improving the degree to which the distributions of the observed and unobserved sets resemble each other.

Abstract: Participatory activity carried out using electronic devices is enhanced by occupying the attention of participants who complete a task before a set completion time. For example, a request or question having an expected response time less than the remaining answer time may be provided to early-finishing participants.

Abstract: Textual responses to open-ended (i.e., free-response) items provided by participants (e.g., by means of mobile wireless devices) are automatically classified, enabling an instructor to assess the responses in a convenient, organized fashion and adjust instruction accordingly.

Abstract: Representative embodiments of a method for grouping participants in an activity include the steps of: (i) defining a grouping policy; (ii) storing, in a database, participant records that include a participant identifier, a characteristic associated with the participant, and/or an identifier for a participant's handheld device; (iii) defining groupings based on the policy and characteristics of the participants relating to the policy and to the activity; and (iv) communicating the groupings to the handheld devices to establish the groups.

Abstract: A compressor that includes a frame, a rotor assembly, and a heat sink assembly. The rotor assembly includes a bearing assembly to which the heat sink assembly is secured. The compressor is configured such that, during use, air is drawn through the interior of the frame. The heat sink assembly then extends radially from the bearing assembly into the air path through the frame such that the air flows over the heat sink assembly.

Abstract: In various embodiments, subject matter for improving discussions in connection with an educational resource is identified and summarized by analyzing annotations made by students assigned to a discussion group to identify high-quality annotations likely to generate responses and stimulate discussion threads, identifying clusters of high-quality annotations relating to the same portion or related portions of the educational resource, extracting and summarizing text from the annotations, and combining, in an electronically represented document, the extracted and summarized text and (i) at least some of the annotations and the portion or portions of the educational resource or (ii) clickable links thereto.

Abstract: In various embodiments, subject matter for improving discussions in connection with an educational resource is identified and summarized by analyzing annotations made by students assigned to a discussion group to identify high-quality annotations likely to generate responses and stimulate discussion threads, identifying clusters of high-quality annotations relating to the same portion or related portions of the educational resource, extracting and summarizing text from the annotations, and combining, in an electronically represented document, the extracted and summarized text and (i) at least some of the annotations and the portion or portions of the educational resource or (ii) clickable links thereto.

Abstract: Embodiments of the invention utilize a feature-extraction approach and/or a matching approach in combination with a nonparametric approach to estimate the proportion of documents in each of multiple labeled categories with high accuracy. The feature-extraction approach automatically generates continuously valued text features optimized for estimating the category proportions, and the matching approach constructs a matched set that closely resembles a data set that is unobserved based on an observed set, thereby improving the degree to which the distributions of the observed and unobserved sets resemble each other.

Abstract: Textual responses to open-ended (i.e., free-response) items provided by participants (e.g., by means of mobile wireless devices) are automatically classified, enabling an instructor to assess the responses in a convenient, organized fashion and adjust instruction accordingly.

Abstract: In various embodiments, subject matter for improving discussions in connection with an educational resource is identified and summarized by analyzing annotations made by students assigned to a discussion group to identify high-quality annotations likely to generate responses and stimulate discussion threads, identifying clusters of high-quality annotations relating to the same portion or related portions of the educational resource, extracting and summarizing text from the annotations, and combining, in an electronically represented document, the extracted and summarized text and (i) at least some of the annotations and the portion or portions of the educational resource or (ii) clickable links thereto.

Abstract: Textual responses to open-ended (i.e., free-response) items provided by participants (e.g., by means of mobile wireless devices) are automatically classified, enabling an instructor to assess the responses in a convenient, organized fashion and adjust instruction accordingly.

Abstract: Representative embodiments of a method for grouping participants in an activity include the steps of: (i) defining a grouping policy; (ii) storing, in a database, participant records that include a participant identifier, a characteristic associated with the participant, and/or an identifier for a participant's handheld device; (iii) defining groupings based on the policy and characteristics of the participants relating to the policy and to the activity; and (iv) communicating the groupings to the handheld devices to establish the groups.

Abstract: In various embodiments, documents are searched and retrieved via receipt of a search query, electronically identifying a reference set of relevant documents, providing a search set of documents, creating a database comprising at least some of the documents of the search set and the reference set, computationally classifying the documents in the database, extracting keywords from the search set and one or more classified sets, optionally filtering the extracted keywords, and electronically identifying at least some of the documents from the database that contain one or more of the extracted keywords.

Abstract: Representative embodiments of a method for grouping participants in an activity include the steps of: (i) defining a grouping policy; (ii) storing, in a database, participant records that include a participant identifier, a characteristic associated with the participant, and/or an identifier for a participant's handheld device; (iii) defining groupings based on the policy and characteristics of the participants relating to the policy and to the activity; and (iv) communicating the groupings to the handheld devices to establish the groups.

Abstract: In various embodiments, online discussions in connection with an educational resource are improved by analyzing annotations made by students assigned to a discussion group to identify high-quality annotations likely to generate responses and stimulate discussion threads and by making the identified annotations visible to students not assigned to the discussion group.

Abstract: A compressor that includes a frame, a rotor assembly, and a heat sink assembly. The rotor assembly includes a bearing assembly to which the heat sink assembly is secured. The compressor is configured such that, during use, air is drawn through the interior of the frame. The heat sink assembly then extends radially from the bearing assembly into the air path through the frame such that the air flows over the heat sink assembly.

Abstract: Participatory activity carried out using electronic devices is enhanced by occupying the attention of participants who complete a task before a set completion time. For example, a request or question having an expected response time less than the remaining answer time may be provided to early-finishing participants.

Abstract: A compressor that includes a frame, a rotor assembly, and a heat sink assembly. The rotor assembly includes a bearing assembly to which the heat sink assembly is secured. The compressor is configured such that, during use, air is drawn through the interior of the frame. The heat sink assembly then extends radially from the bearing assembly into the air path through the frame such that the air flows over the heat sink assembly.

Abstract: Participatory activity carried out using electronic devices is enhanced by occupying the attention of participants who complete a task before a set completion time. For example, a request or question having an expected response time less than the remaining answer time may be provided to early-finishing participants.

Abstract: A compressor that includes a rotor assembly, a stator assembly and a heat sink assembly. The rotor assembly includes a shaft to which a bearing assembly and a rotor core are secured. The heat sink assembly is then secured to the bearing assembly and to the stator assembly.