Tome Sandevski heads the policy engagement unit at Goethe-University Frankfurt, where he coordinates the joint policy engagement projects of the Rhine-Main-Universities Goethe-University Frankfurt, Technical University Darmstadt and Johannes Gutenberg-University Mainz.

• Hearings and similar formats, like expert talks in parliament, are essential ways for members of parliament to gather evidence from scientists.

• The invited experts usually have only a limited amount of time to make their statements and answer questions from members of parliament.

• The committees usually ask to assess past, present or proposed policies (e.g. draft legislation). They often ask for policy recommendations.

• Nowadays, parliaments often publish recordings or minutes of hearings on their websites.

• Hearings can also attract media coverage.

Parliamentary committees organise hearings when assessing past or present policies or preparing new legislation to receive expertise from scientists and stakeholders, who are called witnesses in many English-speaking countries. The scientist can usually submit a brief written statement before the hearing.

Parliamentary staff communicate the dates and time slots to the scientists, who can deliver their expertise in person or virtually. After listening to the invited experts' witness reports, the parliamentary committee members ask the experts questions. The parliamentary committee allocates a minimal amount of time for scientists to present their statements on a policy issue and answer questions from the members of parliament.

Parliaments on the regional and national levels, as well as the European Parliament, usually require external experts to assess policies. Scientists' provision of expertise to members of parliament to improve policies is a critical task. Hearings provide an official channel for presenting evidence to policymakers and engaging in a dialogue with lawmakers. However, scientists must understand that providing evidence and policy recommendations in parliament does not mean policymakers will follow the scientists` assessments when evaluating policies or drafting laws.

Often, citizens can attend hearings. The hearings also attract media attention if they cover controversial topics that have been debated in public before. Many parliaments publish transcripts and recordings on their websites. Many parliaments also offer live streams of hearings. You can also find numerous recordings of parliamentary hearings in various countries on YouTube.

The committees usually grant the experts only a few minutes to make their statements and answer the questions from the members of parliament. Often, the scientists see displays of running clocks or chairs that remind them about the remaining time. Unlike time limits at academic conferences, the chairpersons of the parliamentary committees enforce the time limits, which can be a cultural shock for scientists.

Since the parliamentary committees invited the scientists, scientists may be perceived to be affiliated with certain political parties. While party affiliation is a good thing, some scientists want to avoid leaving the impression of following a party line. Also, heated discussions between scientists and parliament members can occur depending on the political culture in various countries. The opposite can also happen: The members of parliament may have already made up their minds on the respective policy issues and consider the hearing a mandatory but useless exercise, which can be frustrating for scientists as well. Yet, scientists should understand that hearings provide networking opportunities, which scientists should explore. A political science professor once said: "I don't participate in hearings to make a statement in the committee room, but to have informal discussions in the hallways”.

Scientists

If required, scientists must submit a written statement before the hearing. They should prepare brief statements and practice giving short answers. Scientists should also understand that parliament members have limited resources regarding time to read the experts` statements in advance. Scientists must, therefore, not only focus on the content of their written statements but also think about the length and structure of the written statement, visualisations and language. The easier the statement is to read, the more likely the members of parliament will remember the key messages.

Scientists should also consider their role. Do they want to merely provide expertise on a policy issue or advocate for a specific policy outcome? If the latter, they will have to prepare for the hearings by studying draft legislation, the positions of the members of parliament on the policy issues, and the statements provided by the other invited external experts.

Suppose the secretariat of the parliament provides guides or a FAQ question. In that case, scientists should read these documents, which provide helpful information on access to the buildings, time limits, or reimbursements. Suppose the scientist needs additional information on issues like dress code or how to address the members of parliament or the chairperson. In that case, they should contact the staffers organising the hearing. More and more parliaments allow for the virtual participation of scientists. Scientists can often participate virtually. Suppose opportunities arise during coffee breaks or chats in the hallway. In that case, scientists can also ask the staffers of the members of parliament or the parliamentary staffers for feedback regarding their statements.

Support staff (Knowledge exchange managers and research managers)

The members of parliament invite scientists. Often, the members of parliaments ask the support staff or their assistants to identify possible scientists who can be invited. Updated and understandable websites and expert directories are beneficial for staffers at parliaments to identify potential experts. Other factors include fostering connections with members of parliament or staffers in parliaments and publishing policy-relevant and accessible research. Support staff can help organise policy events or communicate the expertise of their scientists via policy events, newsletters, social media posts and other formats. (SEE CHAPTER ON xxx).

Support staff can also keep records of scientists participating in hearings or similar events in parliament to connect scientists participating in hearings for the first time with their peers, who are already familiar with the format. Support staff can also ask the scientists about their experience and write short guides or FAQ lists for their scientists.

Yet scientists can increase their visibility among members of parliament by maintaining understandable websites, publishing policy-relevant research, or actively participating in policy events.

Policymakers

Members of parliament and their support staff have to read the statements in advance and prepare questions they would like to ask the scientists during the hearings.

Required funding for activity

The parliaments usually cover travel expenses and provide a daily allowance.