This page describes how JWST proposals are evaluated. JWST proposals will be reviewed by panels of scientists from the international astronomical and planetary science communities which comprise the Telescope Allocation Committee (TAC). Proposals are reviewed using well-defined Selection Criteria, and the TAC will make recommendations for acceptance to the STScI Director.

How STScI conducts the proposal review

JWST programs are selected through competitive peer review. A broad range of scientists from the international astronomical and planetary science community evaluate and rank all submitted proposals using a well-defined set of criteria and paying special attention to any potential conflicts of interest. The Discussion panels, External panels, and the Executive Committees constitute the Telescope Allocation Committee (TAC) that recommends the science program to the STScI Director. The STScI Director is the Selecting Official for JWST. Based on the recommendations, the Director will make the final allocation of observing time. Full details on the peer review process are given in the JWST Peer Review Guide. 

The Review Panels

Dependent on their size, type, and science category, proposals in JWST Cycle 6 will be reviewed either by a Discussion Panel, an External Panel, or one of the Executive Committees.

Review panels are divided by science category. A high-level description of topical coverage in each panel is given in the following table:

 

The science topics and associated keywords covered by each panel are listed in the Appendix A - Science Categories and Keywords. 

Proposers should note the breadth of topics covered within each science area. Each proposal is read by multiple reviewers. For the Discussion and External panels, all reviewers will have expertise within the broad science area. Few, or even none, may have expertise in the specific subfield of the proposal. For the Executive Committees, all reviewers will have expertise within the field of Galactic or Extragalactic astronomy, but few will have expertise within the broad science area of the proposal, and it is possible none will have expertise in the specific subfield of the proposal. Proposers should take care to write for an appropriately broad audience.

Proposers should note that their proposal may be reviewed by a different topical panel than the one to which it was submitted. Some science cases (and keywords) can span multiple science categories. For proposals whose science goals straddle two separate scientific categories, proposers are encourage to add an alternate science category (and keywords) in APT in addition to the main one. The STScI Science Policy Division (SPD) may determine that a proposal would be better reviewed in a different topical panel given the expertise of the reviewers in both panels.

Discussion Panels

The Cycle 6 discussion-based (i.e., synchronous, but virtual) review is planned to comprise twelve (12) topical panels:

• one (1) Solar System Astronomy;
• one (1) Exoplanet Atmospheres;
• one (1) Exoplanetary Systems;
• two (2) Stars and Stellar Populations;
• two (2) Interstellar Gas and Dust;
• one (1) Galaxy Evolution and the Nearby Universe;
• two (2) Galaxy Frontiers and the Distant Universe;
• two (2) Supermassive Black Holes.

Each panel will be managed by a Panel Chair and Vice Chair, assisted by a Panel Support Scientist and an SPD Panel Manager, and there will be two TAC chairs overseeing the review process, one for the Galactic panels and one for the Extragalactic panels. Panelists are chosen based on their expertise in one or more of the areas under review by the panels.

Each proposal will be assessed by five experts who will grade on an absolute scale against the primary criteria, as discussed below. Based on the preliminary grades, the top-ranked proposals will be discussed during the Discussion Panel meeting. 

The time allocated to each panel is proportional to the time requested by the proposals assigned to that panel. Discussion Panels do not evaluate Large (>130 hours) GO proposals, Treasury GO proposals, AR Legacy proposals, or Pure Parallel proposals, but they will advise their chair on the scientific merit of the subset of those proposals assigned to their panel.

More information about the Discussion Panel review process can be found on the JWST Peer Review Information pages.

External Panels

Each science category has a single External Panel, whose panelists grade proposals asynchronously. Each panel will be assisted by a Panel Support Scientist and an SPD Panel Manager. Panelists are chosen based on their expertise in one or more of the areas under review by the panels.

Each proposal distributed for external review will be assessed by five experts who will grade on an absolute scale against the primary criteria, as discussed below.

The proposals likely to be recommended to the Director for acceptance will be provided to the Panel Chairs of the Discussion Panels of the corresponding Scientific Category prior to the meeting to allow them to identify potential duplications with the proposals reviewed by their panels. 

More information about the External Panel review process can be found on the JWST Peer Review Information pages.

Executive Committees

The Executive Committee (EC) is split into two parts: Galactic EC and Extragalactic EC. Each of the two Executive Committees will include a TAC Chair and the Chairs and Vice Chairs from all the corresponding topical panels. The EC may also include a small number of at-Large members who provide additional scientific expertise and may deputize for conflicted panel chairs if necessary.

The ECs are provided additional input on proposals through feedback from the Discussion Panels via the Panel Chair and Vice Chair.  

More information about the EC review process can be found on the JWST Peer Review Information pages.

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Selection criteria

Primary criteria for all proposals

Each topical panel covers a very broad science category, and each science category contains a number of narrower sub-fields. Ideally a proposal will be impactful to both the narrow sub-field of the proposal and to other sub-fields within the science category or in other science categories. Proposals will be assessed on an absolute scale against three equally-weighted primary criteria with a separate grade given for each.

(A) In-field Impact:

• The scientific merit of the program within its immediate sub-field, and its contribution to advancement of knowledge.
• The immediate sub-field of the proposal is the niche area of the program, not the whole broad science area (e.g. Trans-Neptunian Objects, not Solar System Astronomy).
• Proposals should address how the proposed program will improve understanding of the objects, classes of object, or specialist topics under study, and why the work is relevant and timely.

(B) Out-of-field Impact:

• The program’s impact outside of its immediate sub-field.
• A proposal does not have to impact all of astronomy. The out-of-field impacts could be in other sub-fields within the broader science area of the proposal, or in other broad science areas (e.g. in the case of a TNO proposal, this could be solar system formation or planet formation in general, among others).
• Proposals should discuss implications for other fields or sub-fields, and their breadth, significance, and timeliness.

(C) Suitability & Feasibility:

• The suitability of JWST observations or datasets, or relevance to JWST science. The necessity of special requirements. The feasibility of the science program.
• Proposals should demonstrate that the capabilities of JWST are required to achieve the scientific goals, or demonstrate the relevance of the work to JWST science. Technical issues will be adjudicated by STScI instrument scientists.
• Proposals should include an observing or analysis plan that demonstrates a clear path to science. Proposals should justify time requests and any special requirements, including duplications or joint observatory time.

The final grade is the straight average of these values.

Additional criteria by proposal type

Proposals may be subject to additional criteria, depending on the Proposal Category, as listed below. Letters in square brackets indicate the affected Primary Criteria.

Proposals submitted under one of the Special Initiatives may have additional selection criteria; proposers should consult JWST Special Initiatives for details.

All GO Proposals

• The rationale for selecting the type and number of targets. Reviewers will be instructed to recommend or reject proposals as they are and to refrain from object or hour trimming; therefore, it is very important to strongly justify both the selection and the number of targets in your proposal, as well as the number of hours requested. [C]
• The reasonability of requested resources. [C] 
• The extent to which experimental or supporting ground-based observations (if any) support the science goals of the proposal. [A,B]

Large

• The cohesiveness of the overall work described and the production of appropriate data products and/or tools. [C]
• The utility of the higher-level data products and/or tools. [A,B]

Treasury

• The cohesiveness of the overall work described and the production of appropriate data products and/or tools. [C]
• The utility of the higher-level data products and/or tools. [A,B]
• The extent to which the data products will enable additional scientific investigations and the importance of those investigations. [A,B]
• The level of data products produced and plans for their timely dissemination to the community. High-level science-ready data products should be made available through the MAST data archive or related channels. [C]

Calibration

• The extent to which these observations or analyses enable new types of scientific investigations with JWST and the importance of those observations. [A,B]

Joint Programs

• The extent to which the proposed observations with the Partner Observatory (ALMA, Chandra, HST, NASA-Keck, NOIRLab, NRAO, TESS, and/or XMM-Newton) are critical for the science goals of the proposal. [C]

All Survey Proposals

• The TAC will evaluate the science within the context of the optimal number of targets and minimum number of targets indicated in the Special Requirements Section of the proposal. [C]

All AR Proposals

• The improvement or addition of scientific knowledge with respect to the original use of the data. In particular, a strong justification must be given to reanalyze data if the new project has the same science goals as the original proposal. [A,B]
• A well-developed analysis plan describing how the scientific objectives will be realized. [C]

Legacy

• The cohesiveness of the overall work described and the production of appropriate data products and/or tools. [C]
• The utility of the high-level science-ready data products and/or tools. [A,B]
• The extent to which the data products will enable additional scientific investigations and the importance of those investigations. [A,B]
• The level of data products produced and plans for their timely dissemination to the community. High-level science-ready data products should be made available through the MAST data archive or related channels. [C]

Calibration

• The extent to which these observations or analyses enable new types of scientific investigations with JWST and the importance of those analyses. [A,B]

Theory

• The extent and importance of JWST science investigations enabled by the theoretical analysis and results. [A,B,C] 
• The level of planning for timely dissemination of theoretical results, and possibly software or tools, to the community. [C]

Cloud Computing Studies

• The relevance of the proposed AR Cloud Computing Studies to JWST science investigations and/or data reduction or interpretation. [A,B,C]

Data Science Software

• The relevance of the proposed software development to JWST science investigations and/or data reduction or interpretation. [A,B,C]
• The level of planning for timely dissemination of the proposed software products to the community. [C]

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Recommendations for acceptance

The task of each panel is to provide a rank-ordered list of proposals.

Each panel is allocated a pool of Hours based on the submitted time pressure. Proposals are recommended for acceptance in rank order until the pool of Hours allocated to the panel is exhausted. For an allocation of N hours, the cut-off in ranking is called the "1-N line." There are different Hour pools for Very Small, Small, Medium, and Large + Treasury GO proposals.

Some proposals do not request prime observing hours, including AR, Survey, and Pure Parallel. These programs, together with Calibration programs, cost zero Hours to the panel; however, they are expensive in other resources. As such, all proposals in a panel are ranked together based on their scientific merit, and zero-hour proposals are required to rank competitively with the other accepted programs. That is, only programs ranked above the 1-N line are recommended for acceptance, regardless of their Hour cost.

There are further restrictions on some proposals that are considered across all panels together, such as (Ultra-)Disruptive ToO activations or Survey targets. First, only proposals above the 1-N line in their panel are recommended for acceptance. Then, if the set of all recommended proposals exceed the allowed activations or targets, the panel rankings are used to further down-select proposals until the activation or target limits are not exceeded.

More information can be found on the JWST Peer Review Information pages.

Next: JWST Implementation of Approved Programs

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