Interislander Ferry

Ranking Score Explained

Hi, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

Cymen Crick

Rankers Owner

Valid Reviews

349 Valid Reviews

The Interislander Ferry experience has a total of 360 reviews. There are 349 valid reviews that are included when calculating the ranking score and 11 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 349 valid reviews:

Rating	Count
10/10	40	11%
9/10	81	23%
8/10	103	30%
7/10	62	18%
6/10	29	8%
5/10	16	5%
4/10	7	2%
3/10	5	1%
2/10	2	1%
1/10	4	1%

77.13% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.13% and is based on 349 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 349 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating	Count
10/10	30	10%
9/10	70	23%
8/10	98	32%
7/10	58	19%
6/10	25	8%
5/10	15	5%
4/10	6	2%
3/10	4	1%
2/10	2	1%
1/10	1	0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

73.53%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer	Rating	Age	Relative Weight
Rina	9/10	95 days	100%
edm	1/10	369 days	38%
Colin Barrow	9/10	430 days	90%
Pauline	6/10	583 days	70%
Megan	5/10	735 days	54%
Marjolaine Loitz	4/10	765 days	44%
Keli Knox	10/10	1100 days	36%
Yar	1/10	1314 days	8%
Pinocity	6/10	1679 days	5%
Helen Russell	10/10	1860 days	5%
NewZealander	10/10	2134 days	4%
Tommy Pickett	9/10	2957 days	3%
Tom Bennett	8/10	2961 days	3%
Jeny Smolders	9/10	2963 days	3%
Gregg Wagstaff	7/10	3188 days	2%
Lianne Ijlst	8/10	3216 days	2%
Samantha and Neis	8/10	3217 days	2%
Brandon Cassidy	7/10	3233 days	2%
Vic Baughen	9/10	3235 days	2%
Anders Frank	7/10	3239 days	2%
Dina Schurer	8/10	3240 days	2%
Kim Youngsub	9/10	3241 days	2%
DEBBIE LAMBERT	10/10	3245 days	2%
Gary Williams	8/10	3245 days	2%
Kimberley Gardien	8/10	3252 days	2%
Antoine	9/10	3273 days	2%
Judit Van lanen	9/10	3278 days	2%
Bjorn Nielsen	8/10	3280 days	2%
Joel Virtanen	9/10	3282 days	2%
Corbin Hure	7/10	3282 days	2%
Ron	6/10	3285 days	2%
Thomas Simeon	8/10	3285 days	2%
Suzannah Hill	8/10	3286 days	2%
Kallan Mrozek	9/10	3287 days	2%
Kees Mol	9/10	3291 days	2%
Kristal Lavender	10/10	3291 days	2%
Bastian Bley	9/10	3292 days	2%
Jasmine Rogers	3/10	3293 days	1%
Louis Nilsson	8/10	3297 days	2%
Tim	7/10	3297 days	2%
Jendrik	6/10	3297 days	2%
Katharina	7/10	3298 days	2%
Chris Valchero	9/10	3301 days	2%
Rulp Niet	8/10	3303 days	2%
Soeren Buchheister	9/10	3304 days	2%
Chas Bronson	8/10	3304 days	2%
Jakob Lovdahl	9/10	3306 days	2%
Alexandra Schmidt	10/10	3316 days	2%
Jade Williams	10/10	3317 days	2%
Sam Staines	10/10	3318 days	2%
Nickolas Jonkergouw	7/10	3322 days	2%
Kirsty Smith	10/10	3322 days	2%
Eva Hesse	10/10	3337 days	2%
celine gries	8/10	3337 days	2%
tinagermany111	8/10	3351 days	2%
Cassandra Geyer	8/10	3536 days	2%
Olivier Reculeau	8/10	3537 days	2%
Thomas Michel	5/10	3538 days	1%
Lisa Haedrich	5/10	3542 days	1%
Nadja Guiliani	8/10	3546 days	2%
Elbrich	8/10	3546 days	2%
Jamie Serieux	7/10	3549 days	2%
Adele Jacques	9/10	3550 days	2%
Daniel Weber	6/10	3552 days	1%
Emily Noyd	8/10	3554 days	2%
Aparna Gula	10/10	3555 days	2%
Sebastiaan	7/10	3557 days	2%
Andre	9/10	3558 days	2%
Benedikt Hang	7/10	3559 days	1%
Yannick	8/10	3559 days	2%
S Black	9/10	3560 days	2%
Paul Larauze	6/10	3563 days	1%
Florence	6/10	3564 days	1%
Sarah Kovacs	8/10	3565 days	2%
Frenziska Schmid	7/10	3567 days	1%
Maud Livolsi	7/10	3574 days	1%
Lewis Whittle	6/10	3576 days	1%
Lukas Seager	6/10	3576 days	1%
Andrea Tabaka	8/10	3583 days	2%
Tina Rust	8/10	3585 days	2%
Joel Papak	8/10	3587 days	2%
Clemence and Pedro	9/10	3588 days	2%
Doms Wahlelr	9/10	3590 days	2%
Josef Biller	8/10	3590 days	2%
Justine Hoffmann	8/10	3591 days	2%
Friederike East	7/10	3591 days	1%
Mark White	10/10	3592 days	2%
Briony	8/10	3595 days	2%
Gabriel Siibers	8/10	3595 days	2%
Henry Wichler	8/10	3596 days	2%
Kyle Johnson	9/10	3598 days	2%
Niels Wezenberg	7/10	3599 days	1%
John Hamilton	9/10	3599 days	2%
Brianna Burd	9/10	3599 days	2%
Jessica Ruhland	8/10	3600 days	1%
Stula Vladimir	10/10	3601 days	2%
Cosmo Hartuna	7/10	3603 days	1%
Roland Fischer	6/10	3603 days	1%
Ross Holmes	9/10	3604 days	2%
Tilman	9/10	3606 days	2%
Petru	7/10	3607 days	1%
Fero Saarinen	6/10	3608 days	1%
Lauren Thompson	8/10	3610 days	1%
Meilin	8/10	3613 days	1%
Jonas Hoerning	10/10	3617 days	1%
Vanesha Patel	6/10	3618 days	1%
Mauricio Daniele	9/10	3618 days	1%
Sara and Antoine	8/10	3620 days	1%
Clare Pickford	6/10	3620 days	1%
Daniel Hill	10/10	3621 days	1%
Moritz Braun	7/10	3637 days	1%
Grischa Rodust	8/10	3644 days	1%
Chalie Dotesek	9/10	3645 days	1%
Julien Lafeville	7/10	3649 days	1%
Julia Huesam	8/10	3649 days	1%
Alexandre	9/10	3653 days	1%
Kev Zarka	6/10	3654 days	1%
Markus Wabing	8/10	3657 days	1%
Gessica	6/10	3690 days	1%
Simon Quass	9/10	3694 days	1%
Barthelemy	7/10	3923 days	1%
Brita Topp	10/10	4266 days	0%
Laim Thompson	8/10	4266 days	0%
Adriana	10/10	4274 days	0%
Pavel Jarolimek	5/10	4274 days	0%
Leonie Moeller	6/10	4275 days	0%
Doreen Gendel	8/10	4276 days	0%
Carla Oyarzun	3/10	4279 days	0%
Paolo Cases	3/10	4279 days	0%
Wolfgang and Christine	8/10	4284 days	0%
Helen	8/10	4297 days	0%
Olivier Carval	9/10	4299 days	0%
Hirsch Svenja	9/10	4300 days	0%
Mahr Svenja	8/10	4300 days	0%
Anna Guzewiez	9/10	4316 days	0%
Pier Durand	8/10	4320 days	0%
Serena Poggioli	9/10	4320 days	0%
Wayne Schist	7/10	4320 days	0%
Margreth Lydie	5/10	4328 days	0%
Laura Pleumeekers	7/10	4342 days	0%
David Brooks	10/10	4345 days	0%
Adrien Godeloup	9/10	4354 days	0%
Bet Dreno	8/10	4355 days	0%
Joachim	1/10	4356 days	0%
Pioter Jurkowski	7/10	4356 days	0%
Thomas Roche	9/10	4358 days	0%
Brian	9/10	4417 days	1%
hendrik king	9/10	4540 days	1%
Kiki Wykstra	5/10	4650 days	1%
Galen Licht	4/10	4650 days	1%
Yu-Ti Chu	7/10	4653 days	1%
Ton Martens	7/10	4653 days	1%
Joshua Perry	8/10	4658 days	1%
Molly Ladd	8/10	4658 days	1%
Michael Nolan	9/10	4662 days	1%
Julian Roots	9/10	4662 days	1%
Florent Corino	9/10	4666 days	1%
Amiot Cyriane	7/10	4666 days	1%
Annika	7/10	4666 days	1%
Jonas Herrmann	7/10	4666 days	1%
Matthieu Daveou	8/10	4666 days	1%
Julien Panossian	6/10	4666 days	1%
Raoul Montestruer	5/10	4666 days	1%
Alessa Ndra	8/10	4672 days	1%
Bjorn Hedmark	5/10	4673 days	1%
Evyatar Tulipman	7/10	4675 days	1%
S Curry	10/10	4690 days	1%
Ingrid	9/10	4734 days	1%
Reinier Timmer	7/10	4734 days	1%
Moorman	8/10	4743 days	1%
Stefan Roth	9/10	4768 days	1%
David	9/10	4782 days	1%
kevindang	10/10	4935 days	1%
Ruben Kunze	4/10	5017 days	1%
Sebastian Hol	9/10	5023 days	1%
Dick Stewart	8/10	5032 days	1%
David Beaumont	9/10	5039 days	1%
Beyeler	10/10	5044 days	1%
Nikita Sue	9/10	5049 days	1%
Schweiger	10/10	5051 days	1%
Jan & Marian	10/10	5130 days	1%
Konny	9/10	5134 days	1%
Waldemar Schuler	8/10	5134 days	1%
jule	3/10	5148 days	1%
Jack Potman	8/10	5350 days	1%
Jon_and_Family	9/10	5362 days	1%
Walker	9/10	5365 days	1%
Andreas Blessing	10/10	5373 days	1%
Gema	7/10	5376 days	1%
Avry Fabrice	6/10	5381 days	1%
Diane Johnston	9/10	5386 days	1%
Javier Munoz	8/10	5386 days	1%
Ben Akin-Smith	8/10	5387 days	1%
K Wallis	9/10	5392 days	1%
khs	9/10	5393 days	1%
Emma Ducat	9/10	5393 days	1%
Mr and Mrs Lambert	8/10	5400 days	1%
Andrew Koster	7/10	5406 days	1%
Bakker	8/10	5406 days	1%
Kimberly St Louis	8/10	5407 days	1%
Roel Wesstra	8/10	5413 days	1%
Seifert	10/10	5413 days	1%
Derek Woodward	9/10	5415 days	1%
Fabi & Sabi	8/10	5416 days	1%
Rosey834	8/10	5483 days	1%
Pete & Chris	10/10	5683 days	1%
Tony Masters	9/10	5746 days	1%
Hershell	8/10	5750 days	1%
Mike Robinson	9/10	5751 days	1%
Brent S	2/10	5752 days	0%
Zara Leyden	9/10	5760 days	1%
Judith	7/10	5764 days	1%
anon	8/10	5765 days	1%
Pierre Pilon	8/10	5766 days	1%
Jenny Omb	1/10	5771 days	0%
Frei Urs	6/10	5772 days	1%
Bryan Keddie	9/10	5782 days	1%
Leanne Rogan	5/10	5782 days	1%
Joanne Clarke	8/10	5786 days	1%
Wolfgang G	9/10	5792 days	1%
Thomas Signes	7/10	5813 days	1%
menzel	10/10	5831 days	1%
graemeh1	9/10	5832 days	1%
klinger	10/10	5832 days	1%
gereldineb	8/10	5842 days	1%
jennyb	9/10	5846 days	1%
Frank de Voogd	8/10	5852 days	1%
Jean Paul Mesnage	9/10	5858 days	1%
Hansjoerg Ehrmann	5/10	5859 days	1%
Daniel Alonso	9/10	5860 days	1%
Nigel Petrie	9/10	5871 days	1%
Tracy & Peter Cassidy	8/10	5887 days	1%
miniappleses	8/10	5909 days	1%
Josie Boyle	7/10	6020 days	1%
JanneP	9/10	6090 days	1%
Mikey	9/10	6097 days	1%
SablotniD	7/10	6101 days	1%
WiebkeS	9/10	6108 days	1%
Tanya	5/10	6109 days	1%
Jan	6/10	6109 days	1%
Viola	8/10	6111 days	1%
RowanL	7/10	6112 days	1%
VickiEngland	8/10	6120 days	1%
TomC1	8/10	6125 days	1%
AndyK	9/10	6125 days	1%
TatiamT	9/10	6125 days	1%
GillianK	8/10	6127 days	1%
EelcoK	9/10	6127 days	1%
Michael	9/10	6131 days	1%
soccaplaya14	10/10	6132 days	1%
Eugene	7/10	6133 days	1%
John	6/10	6135 days	1%
Tony	8/10	6140 days	1%
Middleton	4/10	6141 days	1%
Elise	8/10	6142 days	1%
Marie	8/10	6142 days	1%
ThomasS1	10/10	6147 days	1%
RasmusB	4/10	6149 days	1%
Simon	8/10	6154 days	1%
Phil&Joe	10/10	6156 days	1%
Marcus	7/10	6156 days	1%
Andre	7/10	6158 days	1%
Iris	9/10	6160 days	1%
Carla	7/10	6160 days	1%
Sandra	8/10	6164 days	1%
Schaffluber	10/10	6165 days	1%
Hayley	5/10	6166 days	1%
Con	2/10	6210 days	0%
felix	7/10	6211 days	1%
melissa	10/10	6217 days	1%
John B	5/10	6220 days	1%
Gemma	7/10	6258 days	1%
Henry	7/10	6259 days	1%
Antonella	10/10	6266 days	1%
Michelle	8/10	6266 days	1%
Laura	7/10	6275 days	1%
Sarah	8/10	6289 days	1%
Katerina	7/10	6310 days	1%
Erin	3/10	6310 days	1%
Mike Knight	9/10	6331 days	1%
Bronagh Mcartan	8/10	6340 days	1%
Dave	8/10	6351 days	1%
fgregory	10/10	6354 days	1%
Rhea	6/10	6400 days	1%
Georgina Mulligan	8/10	6412 days	1%
Karen C	7/10	6424 days	1%
Edmund Hillstone	10/10	6441 days	1%
Toby	6/10	6464 days	1%
Jennifer Baulch	9/10	6468 days	1%
Susan	8/10	6472 days	1%
Hoetnagels	7/10	6475 days	1%
Alan Bellerby	8/10	6478 days	1%
Sanne Jonker	7/10	6479 days	1%
Renske Tehurne	8/10	6483 days	1%
Benjamin Krein	7/10	6483 days	1%
Anne and Derek	8/10	6484 days	1%
James Davies	7/10	6484 days	1%
Naomi Horton	8/10	6485 days	1%
Roger Repolusk	8/10	6489 days	1%
Tony Wicks	6/10	6489 days	1%
Nancy Dol	8/10	6489 days	1%
Kristine	10/10	6489 days	1%
Kathy Hawey	9/10	6491 days	1%
David Buckley	8/10	6492 days	1%
Lena1	6/10	6492 days	1%
John Woodrow	8/10	6493 days	1%
Carmen Dolny	10/10	6493 days	1%
Haemnerli	8/10	6497 days	1%
Carla	8/10	6504 days	1%
Jim Curley	8/10	6504 days	1%
paulonline	7/10	6510 days	1%
Bex	6/10	6519 days	1%
Jenny Hulsebosch	8/10	6520 days	1%
Melissa Steedman	8/10	6531 days	1%
Tim	7/10	6532 days	1%
Falk Seidel	7/10	6535 days	1%
Hans Olthof	8/10	6535 days	1%
Anu	9/10	6538 days	1%
Anneli	6/10	6540 days	1%
purplekat99	10/10	6548 days	1%
Connor	10/10	6561 days	1%
Ad	7/10	6561 days	1%
Ann Westmacott	5/10	6566 days	1%
Paul Cowie	8/10	6567 days	1%
Ewen Maclean	8/10	6567 days	1%
Sarah Wilton	5/10	6567 days	1%
Arend v Dyn	7/10	6569 days	1%
Linda	8/10	6573 days	1%
Fiona	7/10	6573 days	1%
Ann	7/10	6574 days	1%
ranker_584	9/10	6577 days	1%
Christine	7/10	6577 days	1%
Nina	9/10	6577 days	1%
Anthony	7/10	6582 days	1%
Tom Clements	7/10	6582 days	1%
ranker_46	8/10	6694 days	1%
Pat Brewster	8/10	6694 days	1%
FrankOosterwijk	6/10	6779 days	1%
Kim	8/10	6779 days	1%
Helen	7/10	6810 days	1%
Heather	9/10	6810 days	1%
Helene	9/10	6822 days	1%
John	7/10	6822 days	1%
Giancarlo	6/10	6822 days	1%
Annette	4/10	6846 days	1%
John	5/10	6846 days	1%
Duncan	9/10	6851 days	1%
Jen	4/10	6862 days	1%
Rolf	8/10	6870 days	1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-1.75% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 42 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 86 days. Adjustments are according to the following table.

Days	Adjustment
…	…
83	-1.69%
84	-1.71%
85	-1.73%
86	-1.75%
87	-1.77%
88	-1.79%
89	-1.81%
…	…

Balancing Adjustment

6.05% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

78%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.